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[Illustration: Arms granted to SEBASTIAN DEL CANO, Captain of the
_Victoria_, the first vessel that circumnavigated the Globe
[_For a description, see pp._ 129-30]]
The Story of Geographical Discovery
How the World Became Known
By Joseph Jacobs
With Twenty-four Maps, &c.
PREFACE
In attempting to get what is little less than a history of the world,
from a special point of view, into a couple of hundred duodecimo
pages, I have had to make three bites at my very big cherry. In the
Appendix I have given in chronological order, and for the first
time on such a scale in English, the chief voyages and explorations
by which our knowledge of the world has been increased, and the
chief works in which that knowledge has been recorded. In the body
of the work I have then attempted to connect together these facts
in their more general aspects. In particular I have grouped the
great voyages of 1492-1521 round the search for the Spice Islands
as a central motive. It is possible that in tracing the Portuguese
and Spanish discoveries to the need of titillating the parched
palates of the mediævals, who lived on salt meat during winter and
salt fish during Lent, I may have unduly simplified the problem.
But there can be no doubt of the paramount importance attached
to the spices of the East in the earlier stages. The search for
the El Dorado came afterwards, and is still urging men north to
the Yukon, south to the Cape, and in a south-easterly direction
to "Westralia."
Besides the general treatment in the text and the special details
in the Appendix, I have also attempted to tell the story once more
in a series of maps showing the gradual increase of men's knowledge
of the globe. It would have been impossible to have included all
these in a book of this size and price but for the complaisance
of several publishing firms, who have given permission for the
reproduction on a reduced scale of maps that have already been
prepared for special purposes. I have specially to thank Messrs.
Macmillan for the two dealing with the Portuguese discoveries,
and derived from Mr. Payne's excellent little work on European
Colonies; Messrs. Houghton, Mifflin, & Co., of Boston, for several
illustrating the discovery of America, from Mr. J. Fiske's "School
History of the United States;" and Messrs. Phillips for the arms
of Del Cano, so clearly displaying the "spicy" motive of the first
circumnavigation of the globe.
I have besides to thank the officials of the Royal Geographical
Society, especially Mr. Scott Keltie and Dr. H. R. Mill, for the
readiness with which they have placed the magnificent resources
of the library and map-room of that national institution at my
disposal, and the kindness with which they have answered my queries
and indicated new sources of information.
J. J.
CONTENTS
CHAP.
PREFACE
LIST OF MAPS AND ILLUSTRATIONS
INTRODUCTION
I. THE WORLD AS KNOWN TO THE ANCIENTS
II. THE SPREAD OF CONQUEST IN THE ANCIENT WORLD
III. GEOGRAPHY IN THE DARK AGES
IV. MEDIÆVAL TRAVELS--MARCO POLO, IBN BATUTA
V. ROADS AND COMMERCE
VI. TO THE INDIES EASTWARD--PORTUGUESE ROUTE--PRINCE HENRY AND VASCO
DA GAMA
VII. TO THE INDIES WESTWARD--SPANISH ROUTE--COLUMBUS AND MAGELLAN
VIII. TO THE INDIES NORTHWARD--ENGLISH, FRENCH, DUTCH, AND RUSSIAN ROUTES
IX. PARTITION OF AMERICA
X. AUSTRALIA AND THE SOUTH SEAS--TASMAN AND COOK
XI. EXPLORATION AND PARTITION OF AFRICA--PARK, LIVINGSTON, AND STANLEY
XII. THE POLES--FRANKLIN, ROSS, NORDENSKIOLD, AND NANSEN
ANNALS OF DISCOVERY
LIST OF MAPS AND ILLUSTRATIONS
COAT-OF-ARMS OF DEL CANO (from Guillemard, _Magellan_. By kind
permission of Messrs. Phillips).--It illustrates the importance
attributed to the Spice Islands as the main object of Magellan's
voyage. For the blazon, see pp. 129-30.
THE EARLIEST MAP OF THE WORLD (from the Rev. C. J. Ball's _Bible
Illustrations_, 1898).--This is probably of the eighth century
B.C., and indicates the Babylonian view of the world surrounded by
the ocean, which is indicated by the parallel circles, and traversed
by the Euphrates, which is seen meandering through the middle, with
Babylon, the great city, crossing it at the top. Beyond the ocean
are seven successive projections of land, possibly indicating the
Babylonian knowledge of surrounding countries beyond the Euxine
and the Red Sea.
THE WORLD ACCORDING TO PTOLEMY.--It will be observed that the Greek
geographer regarded the Indian Ocean as a landlocked body of water,
while he appears to have some knowledge of the so ces of the Nile.
The general tendency of the map is to extend Asia very much to
the east, which led to the miscalculation encouraging Columbus to
discover America.
THE ROMAN ROADS OF EUROPE (drawn specially for this work).--These
give roughly the limits within which the inland geographical knowledge
of the ancients reach some degrees of accuracy.
GEOGRAPHICAL MONSTERS (from an early edition of Mandeville's
_Travels_).--Most of the mediæval maps were dotted over with similar
monstrosities.
THE HEREFORD MAP.--This, one of the best known of mediæval maps,
was drawn by Richard of Aldingham about 1307. Like most of these
maps, it has the East with the terrestrial paradise at the top,
and Jerusalem is represented as the centre.
PEUTINGER TABLE, WESTERN PART.--This is the only Roman map extant;
it gives lines of roads from the eastern shores of Britain to the
Adriatic Sea. It is really a kind of bird's-eye view taken from
the African coast. The Mediterranean runs as a thin strip through
the lower part of the map. The lower section joins on to the upper.
THE WORLD ACCORDING TO IBN HAUKAL (from Lelewel, _Géographie du
mon age_).--This map, like most of the Arabian maps, has the south
at the top. It is practically only a diagram, and is thus similar
to the Hereford Map in general form.--Misr=Egypt, Fars=Persia,
Andalus=Spain.
COAST-LINE OF THE MEDITERRANEAN (from the _Portulano_ of Dulcert,
1339, given in Nordenskiold's _Facsimile Atlas_).--To illustrate
the accuracy with which mariners' charts gave the coast-lines as
contrasted with the merely symbolical representation of other mediæval
maps.
FRA MAURO MAP, 1457 (from Lelewel, _loc. Cit._).--Here, as usual,
the south is placed at the top of the map. Besides the ordinary
mediæval conceptions, Fra Mauro included the Portuguese discoveries
along the coast of Africa up to his time, 1457.
PORTUGUESE DISCOVERIES IN AFRICA (from E. J. Payne, _European Colonies_,
1877).--Giving the successive points reached by the Portuguese
navigators during the fifteenth century.
PORTUGUESE INDIES (from Payne, _loc. Cit._).--All the ports mentioned
in ordinary type were held by the Portuguese in the sixteenth century.
THE TOSCANELLI MAP (from Kretschmer, _Entdeckung Amerikas_, 1892).--This
is a reconstruction of the map which Columbus got from the Italian
astronomer and cartographer Toscanelli and used to guide him in
his voyage across the Atlantic. Its general resemblance to the
Behaim Globe will be remarked.
THE BEHAIM GLOBE.--This gives the information about the world possessed
in 1492, just as Columbus was starting, and is mainly based upon the
map of Toscanelli, which served as his guide. It will be observed
that there is no other continent between Spain and Zipangu or Japan,
while the fabled islands of St. Brandan and Antilia are represented
bridging the expanse between the Azores and Japan.
AMERIGO VESPUCCI (from Fiske's _School History of the United States_,
by kind permission of Messrs. Houghton, Mifflin, & Co.)
FERDINAND MAGELLAN (from Fiske's _School History of the United
States_, by kind permission of Messrs. Houghton, Mifflin, & Co.)
MAP OF THE WORLD, from the Ptolemy Edition of 1548 (after Kretschmer's
_Entdeckungsgeschichte Amerikas_).--It will be observed that Mexico
is supposed to be joined on to Asia, and that the North Pacific
was not even known to exist.
RUSSIAN ASIA (after the Atlas published by the Russian Academy of
Sciences in 1737, by kind permission of Messrs. Hachette). Japan
is represented as a peninsula.
AUSTRALIA AS KNOWN IN 1745 (from D'Anville's _Atlas_, by kind permission
of Messrs. Hachette).--It will be seen that the Northern and Western
coasts were even by this time tolerably well mapped out, leaving
only the eastern coast to be explored by Cook.
AUSTRALIA, showing routes of explorations (prepared specially for
the present volume). The names of the chief explorers are given
at the top of the map.
AFRICA AS KNOWN IN 1676 (from Dapper's _Atlas_).--This includes
a knowledge of most of the African river sand lakes due to the
explorations of the Portuguese.
AFRICA (made specially for this volume, to show chief explorations
and partition).--The names of the explorers are given at the foot
of the map itself.
NORTH POLAR REGIONS, WESTERN HALF (prepared specially for the present
volume from the _Citizen's Atlas_, by kind permission of Messrs.
Bartholomew).--This gives the results of the discoveries due to
Franklin expeditions and most of the searchers after the North-West
Passage.
NORTH POLAR REGIONS, EASTERN HALF.--This gives the Siberian coast
investigated by the Russians and Nordenskiold, as well as Nansen's
_Farthest North_.
CLIMBING THE NORTH POLE (prepared specially for this volume). Giving
in graphic form the names of the chief Arctic travellers and the
latitude N. reached from John Davis (1587) to Nansen (1895).
THE STORY OF
GEOGRAPHICAL DISCOVERY
INTRODUCTION
How was the world discovered? That is to say, how did a certain
set of men who lived round the Mediterranean Sea, and had acquired
the art of recording what each generation had learned, become
successively aware of the other parts of the globe? Every part of
the earth, so far as we know, has been inhabited by man during the
five or six thousand years in which Europeans have been storing up
their knowledge, and all that time the inhabitants of each part, of
course, were acquainted with that particular part: the Kamtschatkans
knew Kamtschatka, the Greenlanders, Greenland; the various tribes of
North American Indians knew, at any rate, that part of America over
which they wandered, long before Columbus, as we say, "discovered"
it.
Very often these savages not only know their own country, but can
express their knowledge in maps of very remarkable accuracy. Cortes
traversed over 1000 miles through Central America, guided only by
a calico map of a local cacique. An Eskimo named Kalliherey drew
out, from his own knowledge of the coast between Smith Channel
and Cape York, a map of it, varying only in minute details from
the Admiralty chart. A native of Tahiti, named Tupaia, drew out
for Cook a map of the Pacific, extending over forty-five degrees
of longitude (nearly 3000 miles), giving the relative size and
position of the main islands over that huge tract of ocean. Almost
all geographical discoveries by Europeans have, in like manner,
been brought about by means of guides, who necessarily knew the
country which their European masters wished to "discover."
What, therefore, we mean by the history of geographical discovery is
the gradual bringing to the knowledge of the nations of civilisation
surrounding the Mediterranean Sea the vast tracts of land extending
in all directions from it. There are mainly two divisions of this
history--the discovery of the Old World and that of the New, including
Australia under the latter term. Though we speak of geographical
discovery, it is really the discovery of new tribes of men that
we are thinking of. It is only quite recently that men have sought
for knowledge about lands, apart from the men who inhabit them.
One might almost say that the history of geographical discovery,
properly so called, begins with Captain Cook, the motive of whose
voyages was purely scientific curiosity. But before his time men
wanted to know one another for two chief reasons: they wanted to
conquer, or they wanted to trade; or perhaps we could reduce the
motives to one--they wanted to conquer, because they wanted to
trade. In our own day we have seen a remarkable mixture of all three
motives, resulting in the European partition of Africa--perhaps the
most remarkable event of the latter end of the nineteenth century.
Speke and Burton, Livingstone and Stanley, investigated the interior
from love of adventure and of knowledge; then came the great chartered
trading companies; and, finally, the governments to which these
belong have assumed responsibility for the territories thus made
known to the civilised world. Within forty years the map of Africa,
which was practically a blank in the interior, and, as will be
shown, was better known in 1680 than in 1850, has been filled up
almost completely by researches due to motives of conquest, of
trade, or of scientific curiosity.
In its earlier stages, then, the history of geographical discovery
is mainly a history of conquest, and what we shall have to do will
be to give a short history of the ancient world, from the point
of view of how that world became known. "Became known to whom?"
you may ask; and we must determine that question first. We might,
of course, take the earliest geographical work known to us--the
tenth chapter of Genesis--and work out how the rest of the world
became known to the Israelites when they became part of the Roman
Empire; but in history all roads lead to Rome or away from it,
and it is more useful for every purpose to take Rome as our
centre-point. Yet Rome only came in as the heir of earlier empires
that spread the knowledge of the earth and man by conquest long
before Rome was of importance; and even when the Romans were the
masters of all this vast inheritance, they had not themselves the
ability to record the geographical knowledge thus acquired, and it
is to a Greek named Ptolemy, a professor of the great university
of Alexandria, to whom we owe our knowledge of how much the ancient
world knew of the earth. It will be convenient to determine this
first, and afterwards to sketch rapidly the course of historical
events which led to the knowledge which Ptolemy records.
In the Middle Ages, much of this knowledge, like all other, was
lost, and we shall have to record how knowledge was replaced by
imagination and theory. The true inheritors of Greek science during
that period were the Arabs, and the few additions to real geographical
knowledge at that time were due to them, except in so far as commercial
travellers and pilgrims brought a more intimate knowledge of Asia
to the West.
The discovery of America forms the beginning of a new period, both
in modern history and in modern geography. In the four hundred
years that have elapsed since then, more than twice as much of
the inhabited globe has become known to civilised man than in the
preceding four thousand years. The result is that, except for a few
patches of Africa, South America, and round the Poles, man knows
roughly what are the physical resources of the world he inhabits,
and, except for minor details, the history of geographical discovery
is practically at an end.
Besides its interest as a record of war and adventure, this history
gives the successive stages by which modern men have been made what
they are. The longest known countries and peoples have, on the whole,
had the deepest influence in the forming of the civilised character.
Nor is the practical utility of this study less important. The way
in which the world has been discovered determines now-a-days the
world's history. The great problems of the twentieth century will
have immediate relation to the discoveries of America, of Africa,
and of Australia. In all these problems, Englishmen will have most
to say and to do, and the history of geographical discovery is,
therefore, of immediate and immense interest to Englishmen.
[_Authorities:_ Cooley, _History of Maritime and Inland Discoveries_,
3 vols., 1831; Vivien de Saint Martin, _Histoire de la Géographie_,
1873.]
CHAPTER I
THE WORLD AS KNOWN TO THE ANCIENTS
Before telling how the ancients got to know that part of the world
with which they finally became acquainted when the Roman Empire
was at its greatest extent, it is as well to get some idea of the
successive stages of their knowledge, leaving for the next chapter
the story of how that knowledge was obtained. As in most branches of
organised knowledge, it is to the Greeks that we owe our acquaintance
with ancient views of this subject. In the early stages they possibly
learned something from the Phoenicians, who were the great traders
and sailors of antiquity, and who coasted along the Mediterranean,
ventured through the Straits of Gibraltar, and traded with the
British Isles, which they visited for the tin found in Cornwall. It
is even said that one of their admirals, at the command of Necho,
king of Egypt, circumnavigated Africa, for Herodotus reports that
on the homeward voyage the sun set in the sea on the right hand.
But the Phoenicians kept their geographical knowledge to themselves
as a trade secret, and the Greeks learned but little from them.
The first glimpse that we have of the notions which the Greeks
possessed of the shape and the inhabitants of the earth is afforded
by the poems passing under the name of HOMER. These poems show an
intimate knowledge of Northern Greece and of the western coasts of
Asia Minor, some acquaintance with Egypt, Cyprus, and Sicily; but
all the rest, even of the Eastern Mediterranean, is only vaguely
conceived by their author. Where he does not know he imagines,
and some of his imaginings have had a most important influence
upon the progress of geographical knowledge. Thus he conceives of
the world as being a sort of flat shield, with an extremely wide
river surrounding it, known as Ocean. The centre of this shield
was at Delphi, which was regarded as the "navel" of the inhabited
world. According to Hesiod, who is but little later than Homer, up
in the far north were placed a people known as the _Hyperboreani_, or
those who dwelt at the back of the north wind; whilst a corresponding
place in the south was taken by the Abyssinians. All these four
conceptions had an important influence upon the views that men had
of the world up to times comparatively recent. Homer also mentioned
the pigmies as living in Africa. These were regarded as fabulous,
till they were re-discovered by Dr. Schweinfurth and Mr. Stanley
in our own time.
It is probably from the Babylonians that the Greeks obtained the
idea of an all-encircling ocean. Inhabitants of Mesopotamia would
find themselves reaching the ocean in almost any direction in which
they travelled, either the Caspian, the Black Sea, the Mediterranean,
or the Persian Gulf. Accordingly, the oldest map of the world which
has been found is one accompanying a cuneiform inscription, and
representing the plain of Mesopotamia with the Euphrates flowing
through it, and the whole surrounded by two concentric circles,
which are named briny waters. Outside these, however, are seven
detached islets, possibly representing the seven zones or climates
into which the world was divided according to the ideas of the
Babylonians, though afterwards they resorted to the ordinary four
cardinal points. What was roughly true of Babylonia did not in
any way answer to the geographical position of Greece, and it is
therefore probable that in the first place they obtained their
ideas of the surrounding ocean from the Babylonians.
[Illustration: THE EARLIEST MAP OF THE WORLD]
It was after the period of Homer and Hesiod that the first great
expansion of Greek knowledge about the world began, through the
extensive colonisation which was carried on by the Greeks around
the Eastern Mediterranean. Even to this day the natives of the
southern part of Italy speak a Greek dialect, owing to the wide
extent of Greek colonies in that country, which used to be called
"Magna Grecia," or "Great Greece." Marseilles also one of the Greek
colonies (600 B.C.), which, in its turn, sent out other colonies
along the Gulf of Lyons. In the East, too, Greek cities were dotted
along the coast of the Black Sea, one of which, Byzantium, was
destined to be of world-historic importance. So, too, in North
Africa, and among the islands of the Ægean Sea, the Greeks colonised
throughout the sixth and fifth centuries B.C., and in almost every
case communication was kept up between the colonies and the
mother-country.
Now, the one quality which has made the Greeks so distinguished
in the world's history was their curiosity; and it was natural
that they should desire to know, and to put on record, the large
amount of information brought to the mainland of Greece from the
innumerable Greek colonies. But to record geographical knowledge,
the first thing that is necessary is a map, and accordingly it is
a Greek philosopher named ANAXIMANDER of Miletus, of the sixth
century B.C., to whom we owe the invention of map-drawing. Now,
in order to make a map of one's own country, little astronomical
knowledge is required. As we have seen, savages are able to draw
such maps; but when it comes to describing the relative positions
of countries divided from one another by seas, the problem is not
so easy. An Athenian would know roughly that Byzantium (now called
Constantinople) was somewhat to the east and to the north of him,
because in sailing thither he would have to sail towards the rising
sun, and would find the climate getting colder as he approached
Byzantium. So, too, he might roughly guess that Marseilles was
somewhere to the west and north of him; but how was he to fix the
relative position of Marseilles and Byzantium to one another? Was
Marseilles more northerly than Byzantium? Was it very far away
from that city? For though it took longer to get to Marseilles,
the voyage was winding, and might possibly bring the vessel
comparatively near to Byzantium, though there might be no direct
road between the two cities. There was one rough way of determining
how far north a place stood: the very slightest observation of the
starry heavens would show a traveller that as he moved towards
the north, the pole-star rose higher up in the heavens. How much
higher, could be determined by the angle formed by a stick pointing
to the pole-star, in relation to one held horizontally. If, instead
of two sticks, we cut out a piece of metal or wood to fill up the
enclosed angle, we get the earliest form of the sun-dial, known as
the _gnomon_, and according to the shape of the gnomon the latitude
of a place is determined. Accordingly, it is not surprising to find
that the invention of the gnomon is also attributed to Anaximander,
for without some such instrument it would have been impossible for
him to have made any map worthy of the name. But it is probable
that Anaximander did not so much invent as introduce the gnomon,
and, indeed, Herodotus, expressly states that this instrument was
derived from the Babylonians, who were the earliest astronomers, so
far as we know. A curious point confirms this, for the measurement
of angles is by degrees, and degrees are divided into sixty seconds,
just as minutes are. Now this division into sixty is certainly
derived from Babylonia in the case of time measurement, and is
therefore of the same origin as regards the measurement of angles.
We have no longer any copy of this first map of the world drawn
up by Anaximander, but there is little doubt that it formed the
foundation of a similar map drawn by a fellow-townsman of Anaximander,
HECATÆUS of Miletus, who seems to have written the first formal
geography. Only fragments of this are extant, but from them we are
able to see that it was of the nature of a _periplus_, or seaman's
guide, telling how many days' sail it was from one point to another,
and in what direction. We know also that he arranged his whole
subject into two books, dealing respectively with Europe and Asia,
under which latter term he included part of what we now know as
Africa. From the fragments scholars have been able to reproduce
the rough outlines of the map of the world as it presented itself
to Hecatæus. From this it can be seen that the Homeric conception of
the surrounding ocean formed a chief determining feature in Hecatæus's
map. For the rest, he was acquainted with the Mediterranean, Red,
and Black Seas, and with the great rivers Danube, Nile, Euphrates,
Tigris, and Indus.
The next great name in the history of Greek geography is that of
HERODOTUS of Halicarnassus, who might indeed be equally well called
the Father of Geography as the Father of History. He travelled
much in Egypt, Babylonia, Persia, and on the shores of the Black
Sea, while he was acquainted with Greece, and passed the latter
years of his life in South Italy. On all these countries he gave
his fellow-citizens accurate and tolerably full information, and
he had diligently collected knowledge about countries in their
neighbourhood. In particular he gives full details of Scythia (or
Southern Russia), and of the satrapies and royal roads of Persia.
As a rule, his information is as accurate as could be expected at
such an early date, and he rarely tells marvellous stories, or if
he does, he points out himself their untrustworthiness. Almost the
only traveller's yarn which Herodotus reports without due scepticism
is that of the ants of India that were bigger than foxes and burrowed
out gold dust for their ant-hills.
One of the stories he relates is of interest, as seeming to show
an anticipation of one of Mr. Stanley's journeys. Five young men
of the Nasamonians started from Southern Libya, W. of the Soudan,
and journeyed for many days west till they came to a grove of trees,
when they were seized by a number of men of very small stature, and
conducted through marshes to a great city of black men of the same
size, through which a large river flowed. This Herodotus identifies
with the Nile, but, from the indication of the journey given by
him, it would seem more probable that it was the Niger, and that
the Nasamonians had visited Timbuctoo! Owing to this statement
of Herodotus, it was for long thought that the Upper Nile flowed
east and west.
After Herodotus, the date of whose history may be fixed at the
easily remembered number of 444 B.C., a large increase of knowledge
was obtained of the western part of Asia by the two expeditions of
Xenophon and of Alexander, which brought the familiar knowledge of
the Greeks as far as India. But besides these military expeditions
we have still extant several log-books of mariners, which might
have added considerably to Greek geography. One of these tells
the tale of an expedition of the Carthaginian admiral named Hanno,
down the western coast of Africa, as far as Sierra Leone, a voyage
which was not afterwards undertaken for sixteen hundred years.
Hanno brought back from this voyage hairy skins, which, he stated,
belonged to men and women whom he had captured, and who were known
to the natives by the name of Gorillas. Another log-book is that
of a Greek named Scylax, who gives the sailing distances between
nearly all ports on the Mediterranean and Black Seas, and the number
of days required to pass from one to another. From this it would seem
that a Greek merchant vessel could manage on the average fifty miles
a day. Besides this, one of Alexander's admirals, named Nearchus,
learned to carry his ships from the mouth of the Indus to the Arabian
Gulf. Later on, a Greek sailor, Hippalus, found out that by using
the monsoons at the appropriate times, he could sail direct from
Arabia to India without laboriously coasting along the shores of
Persia and Beluchistan, and in consequence the Greeks gave his
name to the monsoon. For information about India itself, the Greeks
were, for a long time, dependent upon the account of Megasthenes,
an ambassador sent by Seleucus, one of Alexander's generals, to
the Indian king of the Punjab.
While knowledge was thus gained of the East, additional information
was obtained about the north of Europe by the travels of one PYTHEAS,
a native of Marseilles, who flourished about the time of Alexander
the Great (333 B.C.), and he is especially interesting to us as
having been the first civilised person who can be identified as
having visited Britain. He seems to have coasted along the Bay
of Biscay, to have spent some time in England,--which he reckoned
as 40,000 stadia (4000 miles) in circumference,--and he appears
also to have coasted along Belgium and Holland, as far as the mouth
of the Elbe. Pytheas is, however, chiefly known in the history
of geography as having referred to the island of Thule, which he
described as the most northerly point of the inhabited earth, beyond
which the sea became thickened, and of a jelly-like consistency. He
does not profess to have visited Thule, and his account probably
refers to the existence of drift ice near the Shetlands.
All this new information was gathered together, and made accessible
to the Greek reading world, by ERATOSTHENES, librarian of Alexandria
(240-196 B.C.), who was practically the founder of scientific geography.
He was the first to attempt any accurate measurement of the size of
the earth, and of its inhabited portion. By his time the scientific
men of Greece had become quite aware of the fact that the earth
was a globe, though they considered that it was fixed in space
at the centre of the universe. Guesses had even been made at the
size of this globe, Aristotle fixing its circumference at 400,000
stadia (or 40,000 miles), but Eratosthenes attempted a more accurate
measurement. He compared the length of the shadow thrown by the sun
at Alexandria and at Syene, near the first cataract of the Nile,
which he assumed to be on the same meridian of longitude, and to be
at about 5000 stadia (500 miles) distance. From the difference in
the length of the shadows he deduced that this distance represented
one-fiftieth of the circumference of the earth, which would accordingly
be about 250,000 stadia, or 25,000 geographical miles. As the actual
circumference is 24,899 English miles, this was a very near
approximation, considering the rough means Eratosthenes had at his
disposal.
Having thus estimated the size of the earth, Eratosthenes then
went on to determine the size of that portion which the ancients
considered to be habitable. North and south of the lands known to
him, Eratosthenes and all the ancients considered to be either
too cold or too hot to be habitable; this portion he reckoned to
extend to 38,000 stadia, or 3800 miles. In reckoning the extent
of the habitable portion from east to west, Eratosthenes came to
the conclusion that from the Straits of Gibraltar to the east of
India was about 80,000 stadia, or, roughly speaking, one-third of
the earth's surface. The remaining two-thirds were supposed to be
covered by the ocean, and Eratosthenes prophetically remarked that
"if it were not that the vast extent of the Atlantic Sea rendered it
impossible, one might almost sail from the coast of Spain to that
of India along the same parallel." Sixteen hundred years later, as
we shall see, Columbus tried to carry out this idea. Eratosthenes
based his calculations on two fundamental lines, corresponding in a
way to our equator and meridian of Greenwich: the first stretched,
according to him, from Cape St. Vincent, through the Straits of
Messina and the island of Rhodes, to Issus (Gulf of Iskanderun); for
his starting-line in reckoning north and south he used a meridian
passing through the First Cataract, Alexandria, Rhodes, and Byzantium.
The next two hundred years after Eratosthenes' death was filled
up by the spread of the Roman Empire, by the taking over by the
Romans of the vast possessions previously held by Alexander and
his successors and by the Carthaginians, and by their spread into
Gaul, Britain, and Germany. Much of the increased knowledge thus
obtained was summed up in the geographical work of STRABO, who
wrote in Greek about 20 B.C. He introduced from the extra knowledge
thus obtained many modifications of the system of Eratosthenes,
but, on the whole, kept to his general conception of the world. He
rejected, however, the existence of Thule, and thus made the world
narrower; while he recognised the existence of Ierne, or Ireland;
which he regarded as the most northerly part of the habitable world,
lying, as he thought, north of Britain.
Between the time of Strabo and that of Ptolemy, who sums up all
the knowledge of the ancients about the habitable earth, there was
only one considerable addition to men's acquaintance with their
neighbours, contained in a seaman's manual for the navigation of
the Indian Ocean, known as the _Periplus_ of the Erythræan Sea.
This gave very full and tolerably accurate accounts of the coasts
from Aden to the mouth of the Ganges, though it regarded Ceylon
as much greater, and more to the south, than it really is; but
it also contains an account of the more easterly parts of Asia,
Indo-China, and China itself, "where the silk comes from." This
had an important influence on the views of Ptolemy, as we shall
see, and indirectly helped long afterwards to the discovery of
America.
[Illustration: PTOLEMAEI ORBIS]
It was left to PTOLEMY of Alexandria to sum up for the ancient
world all the knowledge that had been accumulating from the time
of Eratosthenes to his own day, which we may fix at about 150 A.D.
He took all the information he could find in the writings of the
preceding four hundred years, and reduced it all to one uniform
scale; for it is to him that we owe the invention of the method
and the names of latitude and longitude. Previous writers had been
content to say that the distance between one point and another
was so many stadia, but he reduced all this rough reckoning to
so many degrees of latitude and longitude, from fixed lines as
starting-points. But, unfortunately, all these reckonings were
rough calculations, which are almost invariably beyond the truth;
and Ptolemy, though the greatest of ancient astronomers, still
further distorted his results by assuming that a degree was 500
stadia, or 50 geographical miles. Thus when he found in any of
his authorities that the distance between one port and another was
500 stadia, he assumed, in the first place, that this was accurate,
and, in the second, that the distance between the two places was
equal to a degree of latitude or longitude, as the case might be.
Accordingly he arrived at the result that the breadth of the habitable
globe was, as he put it, twelve hours of longitude (corresponding
to 180°)--nearly one-third as much again as the real dimensions
from Spain to China. The consequence of this was that the distance
from Spain to China _westward_ was correspondingly diminished by
sixty degrees (or nearly 4000 miles), and it was this error that
ultimately encouraged Columbus to attempt his epoch-making voyage.
Ptolemy's errors of calculation would not have been so extensive
but that he adopted a method of measurement which made them
accumulative. If he had chosen Alexandria for the point of departure
in measuring longitude, the errors he made when reckoning westward
would have been counterbalanced by those reckoning eastward, and
would not have resulted in any serious distortion of the truth; but
instead of this, he adopted as his point of departure the Fortunatæ
Insulæ, or Canary Islands, and every degree measured to the east
of these was one-fifth too great, since he assumed that it was
only fifty miles in length. I may mention that so great has been
the influence of Ptolemy on geography, that, up to the middle of
the last century, Ferro, in the Canary Islands, was still retained
as the zero-point of the meridians of longitude.
Another point in which Ptolemy's system strongly influenced modern
opinion was his departure from the previous assumption that the
world was surrounded by the ocean, derived from Homer. Instead
of Africa being thus cut through the middle by the ocean, Ptolemy
assumed, possibly from vague traditional knowledge, that Africa
extended an unknown length to the south, and joined on to an equally
unknown continent far to the east, which, in the Latinised versions
of his astronomical work, was termed "terra australis incognita,"
or "the unknown south land." As, by his error with regard to the
breadth of the earth, Ptolemy led to Columbus; so, by his mistaken
notions as to the "great south land," he prepared the way for the
discoveries of Captain Cook. But notwithstanding these errors,
which were due partly to the roughness of the materials which he
had to deal with, and partly to scientific caution, Ptolemy's work
is one of the great monuments of human industry and knowledge. For
the Old World it remained the basis of all geographical knowledge
up to the beginning of the last century, just as his astronomical
work was only finally abolished by the work of Newton. Ptolemy
has thus the rare distinction of being the greatest authority on
two important departments of human knowledge--astronomy and
geography--for over fifteen hundred years. Into the details of
his description of the world it is unnecessary to go. The map will
indicate how near he came to the main outlines of the Mediterranean,
of Northwest Europe, of Arabia, and of the Black Sea. Beyond these
regions he could only depend upon the rough indications and guesses
of untutored merchants. But it is worth while referring to his method
of determining latitude, as it was followed up by most succeeding
geographers. Between the equator and the most northerly point known
to him, he divides up the earth into horizontal strips, called
by him "climates," and determined by the average length of the
longest day in each. This is a very rough method of determining
latitude, but it was probably, in most cases, all that Ptolemy
had to depend upon, since the measurement of angles would be a
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