Slide #113
TITLE: Crates' Globe
DATE: 180-150 B.C.
AUTHOR: Crates of Mallos
DESCRIPTION: These slides show modern reconstructions of the globe of
Crates of Mallos, which was originally constructed at Pergamum in Asia Minor
in 180 B.C. The various measurements of the earth's size by Eratosthenes
raised a curious problem. The known dimensions of the oikumene [inhabited
world] were too small relative to the estimated size of the earth sphere,
the oikumene occupied only one quadrant of the sphere. Such an imbalance
in a spherical object was contrary to the Greek sense of symmetry. Crates,
therefore, solved the problem on his globe by drawing three other "continents
" (an anticipation/prediction of the existence of the Americas, Antarctica
and Australia) to provide the necessary "balance" and symmetry.
Here was born the concept of the "Antipodes", or the great southern
continent, the "Terra Australis", that would be conjured up in
medieval and renaissance period maps.
It appears to have been the polymath grammarian Crates of Mallos, a contemporary
of Hipparchus, and a member of the Stoic School of Philosophers, who made
the first recorded attempt to construct a terrestrial globe, and that he
exhibited the same in Pergamum, not far from the year 150 B.C. About 168
B.C. Crates, who wrote among other things on Homer and the wanderings of
Odysseus, visited Rome. He was professionally interested in the city's drainage
system, but while exploring the Cloaca Maxima broke his leg. He used the
period of recovery to give lectures in Rome, which are said to have created
a great impression. His view of terrestrial mapping was that the shape could
only be right if it was drawn on a globe, and eventually that the scale
could only be effective if the globe was at least ten feet in diameter.
In designing his 'orb', if indeed he put his theory into practice, Crates
favored an unusual form of symmetry. There were, he said, separated by two
intersecting belts of ocean, four symmetrical landmasses: (a) Europe, Asia
and the part of Africa known at that time; (b) south of them, that of the
Antoikoi, 'dwellers opposite'; (c) west of them, the Perioikoi,
'dwellers round'; (d) south of the Perioikoi, the Antipodes.
The break between the landmass known at that time and that of the Antoikoi
came, according to him, at a belt on each side of the equator, and there
were Ethiopians (Aethiopes, 'black-faces') on each side of
this water divide. Homer had written of the Ethiopians, split in
two, some in the East, some by the setting sun. Later Greek writers interpreted
this passage in various ways. No doubt, as a Homeric scholar, Crates was
more concerned to give a plausible account of Homeric descriptions than
to investigate explanations which suggested the existence of a continuous
African landmass stretching across the equator. The idea however, was taken
up by Cicero in the somnium Scipionis [ 'Dream of Scipio'] which
he incorporated in his De republica. When Macrobius wrote a commentary
on the somnium Scipionis about AD 390, he defended and amplified
Crates' theory, aspects of which thus found their way into medieval cartography;
the Perioikoi and Antipodes were then omitted, although discussed
by Cicero and Macrobius (Slide #201).
It seems to have been Crates' idea that the earth's surface, when represented
on a sphere, should appear as divided into four island-like habitable regions.
On the one hemisphere, which is formed by a meridional plane cutting the
sphere, lies our own oikumene, and that of the Antoecians
in corresponding longitude and in opposite latitude; on the other hemisphere
lies the oikumene of the Perioecians in our latitude and in
opposite longitude, and that of the Antipodes in latitude and longitude
opposite to us. Through the formulation and expression of such a theory
the existence of an antipodal people was put forth as a speculative problem,
an idea frequently discussed in the Middle Ages, and settled only by the
actual discovery of antipodal regions and antipodal peoples in the day of
great transoceanic discoveries of the 17th and 18th centuries.
A belief in the existence of antipodal peoples, very clearly was also accepted
by Pythagoras, Eratosthenes, Posidonius, Aristotle, Strabo, and later Capella.
Numerous others presupposed the earth to be globular in shape. [see Kretschmer,
K., Die physische Erdkunde im christlichen Mittelalter. Wien, 1889.
pp. 54-59, wherein the author gives consideration to the doctrine of the
Antipodes as held in the Middle Ages. Berger, Geschichte,
pt. 3, p. 129, notes that the idea of the earth's division into four parts
or quarters persisted for centuries after Crates' day, if not among scientific
geographers, at least among those who could be said to have possessed general
culture. Cleomedes, Ampelius, Nonnus, and Eumenius mention the idea as one
to be accepted.
It was thought that Africa did not extend to the equator, or at least was
not habitable to the equator. Below the equator there was thought to be
water but beyond the uninhabitable and impassable torrid zone, a habitable
region existed. The map of Lambertus (Slide
#217) well represents this early theory. Pomponius Mela (Slide
#116) called the inhabitants of this southern region Antichthoni,
their country being unknown to us because of the torrid zone intervening.
Pliny, and after him Solinus, says that for a long time the island of Taprobana
[Ceylon/Sri Lanka] was thought to be the region occupied by the Antichthoni.
That Strabo (Slide #115), at a later date, had this
Pergamenian example in mind when stating certain rules to be observed in
the construction of globes seems probable, since he makes mention of Crates'
globe. Strabo alone among ancient writers, so far as we at presently know,
treats terrestrial globes practically. He thought that a globe to be serviceable
should be of large size, and his reasoning can readily be understood, for
what at that time was really known of the earth's surface was small indeed
in comparison with what was unknown. Should one not make use of a sphere
of large dimensions, the habitable regions in comparison with the earth's
entire surface, would occupy but small space. What Strabo states in his
geography is interesting and may here well be cited.
Whoever would represent the real earth as near as possible by artificial
means, should make a sphere like that of Crates, and upon this draw the
quadrilateral within which his chart of geography is to be placed. For this
purpose however a large globe is necessary since the section mentioned,
though but a very small portion of the entire sphere, must be capable of
containing properly all the regions of the habitable earth and of presenting
an accurate view of them to those who wish to consult it. Anyone who is
able will certainly do well to obtain such a globe. But it should have a
diameter of not less than ten feet; those who cannot obtain a globe of this
size, or one nearly as large, had better draw their charts on a plane surface
of not less than seven feet. Draw straight lines for the parallels, and
others at right angles to these. We can easily imagine how the eye can transfer
the figure and extent (of these lines) from a plane surface to one that
is spherical. The meridians of each country on the globe have a tendency
to unite in a single point at the poles; nevertheless on the surface of
a plane map there would be no advantage if the right lines alone which should
represent the meridians were drawn slightly to converge.
Crates' motive for his cartography was partly literary, interpreting Ulysses'
wanderings, and historical rather than purely scientific. As a Stoic, he
proclaimed Homer the founder of geography, crediting him with belief in
a spherical earth and commenting on his poems accordingly. To explain Homer's
line, "The Ethiopians who dwell sundered in twain, the farthermost
of men", Crates argued that on each side of an equatorial ocean there
lived the Ethiopians, divided by the ocean, one group in the Northern Hemisphere,
the other group in the Southern, without any interchange between them. Again
Strabo reports:
Crates, following the mere form of mathematical demonstration, says that
the torrid zone is "occupied" by Oceanus, and that on both sides
of this zone are the temperate zones, the one being on our side, while the
other is on the opposite side of it. Now, just as these Ethiopians on our
side of Oceanus, who face the south throughout the whole length of the inhabited
world, are called the most remote of the one group of peoples, since they
dwell on the shores of Oceanus, so too, Crates thinks, we must conceive
that on the other side of Oceanus also there are Ethiopians, the most remote
of the other group of peoples in the temperate zone, since they dwell on
the shores of this same Oceanus.
The scientific thinking behind the geography of Crates' globe was derived
directly from the teaching of Eratosthenes about the relative size of the
known world. By combining the geometric approach of his predecessor with
his own interpretation of Homer (Slide #105), he
represented four inhabited worlds on the surface of his terrestrial globe.
Two were in the Northern Hemisphere, the one where the Greeks lived, occupying
far less than half of the Northern Hemisphere, and another symmetrically
situated in the other half. Two other inhabited worlds are found in the
Southern Hemisphere, symmetrical with the two north of the equator. These
four worlds were separated by oceans along the equator (occupying the torrid
zone made uninhabitable by heat) and along a meridian. The inhabited areas
were thus islands, with no communication between them.
It is clear that this conception of four symmetrical land areas was a direct
consequence of the geometry of the sphere and the size Eratosthenes attributed
to the inhabited world in relation to the total globe. Crates demonstrated
this by drawing the four areas on the surface of his globe and suggesting
that the three unknown lands could be similar to the known one. To give
it further credibility, he also drew in the main parallel circles, emphasizing
those defining the zones: these were the tropics (at 24° distance from
the equator), between which flowed the Ocean as envisaged by Homer, and
the two polar circles (at 66° distance from the equator).
Crates' globe was thus a product of theoretical mathematical cartography,
communicating an image of the world that was very far from reality. Our
understanding of the globe's physical characteristics is meager, and there
is no evidence to suggest how or of what material it was made, but its influence
on the history of cartographic thought has been considerable. The concept
of the equatorial ocean was transmitted to medieval Europe through Macrobius'
commentary on Cicero's Dream of Scipio. Scholars of later times also
vied eagerly to give adequate names to these unknown worlds, but on the
whole they did not doubt their existence.
LOCATION: (this globe only exists as a reconstruction)
REFERENCES:
Bagrow, L., History of Cartography, p. 33.
*Bunbury, E., History of Ancient Geography, Chapter V.
*Dilke, O.A.W., Greek and Roman Maps, p. 36.
Landström, B., Bold Voyages and Great Explorers, p. 43.
*Raisz, E., General Cartography, p. 10.
*Stevenson, E., Terrestrial Globes, p. 7.
*illustrated