STRABO THE GEOGRAPHER
The earliest of these workers in point of time is
Strabo. This most famous of ancient geographers
was born in Amasia, Pontus, about 63 B.C., and lived
to the year 24 A.D., living, therefore, in the age of
Cæsar and Augustus, during which the final transformation
in the political position of the kingdom of
Egypt was effected. The name of Strabo in a modified
form has become popularized through a curious
circumstance. The geographer, it appears, was afflicted
with a peculiar squint of the eyes, hence the name
strabismus, which the modern oculist applies to that
particular infirmity.
Fortunately, the great geographer has not been
forced to depend upon hearsay evidence for recognition.
His comprehensive work on geography has
been preserved in its entirety, being one of the few
expansive classical writings of which this is true. The
other writings of Strabo, however, including certain
histories of which reports have come down to us, are
entirely lost. The geography is in many ways a remarkable
book. It is not, however, a work in which
any important new principles are involved. Rather
is it typical of its age in that it is an elaborate compilation
and a critical review of the labors of Strabo's
predecessors. Doubtless it contains a vast deal of new
information as to the details of geography—precise
areas and distance, questions of geographical locations
as to latitude and zones, and the like. But however
important these details may have been from a contemporary
stand-point, they, of course, can have nothing
more than historical interest to posterity. The
value of the work from our present stand-point is chiefly
due to the criticisms which Strabo passes upon his forerunners,
and to the incidental historical and scientific
references with which his work abounds. Being
written in this closing period of ancient progress, and
summarizing, as it does, in full detail the geographical
knowledge of the time, it serves as an important
guide-mark for the student of the progress of scientific
thought. We cannot do better than briefly to follow
Strabo in his estimates and criticisms of the work of
his predecessors, taking note thus of the point of view
from which he himself looked out upon the world.
We shall thus gain a clear idea as to the state of scientific
geography towards the close of the classical epoch.
"If the scientific investigation of any subject be the
proper avocation of the philosopher,'' says Strabo,
"geography, the science of which we propose to treat,
is certainly entitled to a high place; and this is evident
from many considerations. They who first undertook
to handle the matter were distinguished men.
Homer, Anaximander the Milesian, and Hecæus (his
fellow-citizen according to Eratosthenes), Democritus,
Eudoxus, Dicæarchus, and Ephorus, with many
others, and after these, Eratosthenes, Polybius, and
Posidonius, all of them philosophers. Nor is the
great learning through which alone this subject can be
approached possessed by any but a person acquainted
with both human and divine things, and these attainments
constitute what is called philosophy. In addition
to its vast importance in regard to social life and
the art of government, geography unfolds to us a celestial
phenomena, acquaints us with the occupants of
the land and ocean, and the vegetation, fruits, and
peculiarities of the various quarters of the earth, a
knowledge of which marks him who cultivates it as
a man earnest in the great problem of life and happiness.''
Strabo goes on to say that in common with other
critics, including Hipparchus, he regards Homer as the
first great geographer. He has much to say on the
geographical knowledge of the bard, but this need not
detain us. We are chiefly concerned with his comment
upon his more recent predecessors, beginning with
Eratosthenes. The constant reference to this worker
shows the important position which he held. Strabo
appears neither as detractor nor as partisan, but as one
who earnestly desires the truth. Sometimes he seems
captious in his criticisms regarding some detail, nor is
he always correct in his emendations of the labors of
others; but, on the whole, his work is marked by an
evident attempt at fairness. In reading his book,
however, one is forced to the conclusion that Strabo is
an investigator of details, not an original thinker. He
seems more concerned with precise measurements than
with questionings as to the open problems of his science.
Whatever he accepts, then, may be taken as virtually
the stock doctrine of the period.
"As the size of the earth,'' he says, "has been demonstrated
by other writers, we shall here take for granted
and receive as accurate what they have advanced. We
shall also assume that the earth is spheroidal, that its
surface is likewise spheroidal and, above all, that bodies
have a tendency towards its centre, which latter point
is clear to the perception of the most average
understanding. However, we may show summarily that
the earth is spheroidal, from the consideration that all
things, however distant, tend to its centre, and that
every body is attracted towards its centre by gravity.
This is more distinctly proved from observations of
the sea and sky, for here the evidence of the senses and
common observation is alone requisite. The convexity
of the sea is a further proof of this to those who
have sailed, for they cannot perceive lights at a distance
when placed at the same level as their eyes, and
if raised on high they at once become perceptible to
vision though at the same time farther removed. So
when the eye is raised it sees what before was utterly
imperceptible. Homer speaks of this when he says:
" `Lifted up on the vast wave he quickly beheld afar.'
Sailors as they approach their destination behold the
shore continually raising itself to their view, and objects
which had at first seemed low begin to lift themselves.
Our gnomons, also, are, among other things,
evidence of the revolution of the heavenly bodies, and
common-sense at once shows us that if the depth of the
earth were infinite such a revolution could not take
place.''
[69]
Elsewhere Strabo criticises Eratosthenes for having
entered into a long discussion as to the form of the
earth. This matter, Strabo thinks, "should have been
disposed of in the compass of a few words.'' Obviously
this doctrine of the globe's sphericity had, in the course
of 600 years, become so firmly established among the
Greek thinkers as to seem almost axiomatic. We
shall see later on how the Western world made a curious
recession from this seemingly secure position under
stimulus of an Oriental misconception. As to the size
of the globe, Strabo is disposed to accept without
particular comment the measurements of Eratosthenes.
He speaks, however, of "more recent measurements,''
referring in particular to that adopted by Posidonius,
according to which the circumference is only about
one hundred and eighty thousand stadia. Posidonius,
we may note in passing, was a contemporary and
friend of Cicero, and hence lived shortly before the
time of Strabo. His measurement of the earth was
based on observations of a star which barely rose above
the southern horizon at Rhodes as compared with the
height of the same star when observed at Alexandria.
This measurement of Posidonius, together with the
even more famous measurement of Eratosthenes, appears
to have been practically the sole guide as to the
size of the earth throughout the later periods of antiquity,
and, indeed, until the later Middle Ages.
As becomes a writer who is primarily geographer and
historian rather than astronomer, Strabo shows a
much keener interest in the habitable portions of the
globe than in the globe as a whole. He assures us that
this habitable portion of the earth is a great island,
"since wherever men have approached the termination
of the land, the sea, which we designate ocean, has
been met with, and reason assures us of the similarity
of this place which our senses have not been tempted
to survey.'' He points out that whereas sailors have
not circumnavigated the globe, that they had not been
prevented from doing so by any continent, and it seems
to him altogether unlikely that the Atlantic Ocean is
divided into two seas by narrow isthmuses so placed as
to prevent circumnavigation. "How much more probable
that it is confluent and uninterrupted. This
theory,'' he adds, "goes better with the ebb and flow
of the ocean. Moreover (and here his reasoning becomes
more fanciful), the greater the amount of moisture
surrounding the earth, the easier would the heavenly
bodies be supplied with vapor from thence.'' Yet
he is disposed to believe, following Plato, that the
tradition "concerning the island of Atlantos might be
received as something more than idle fiction, it having
been related by Solon, on the authority of the Egyptian
priests, that this island, almost as large as a continent,
was formerly in existence although now it had disappeared.''
[70]
In a word, then, Strabo entertains no doubt whatever
that it would be possible to sail around the globe
from Spain to India. Indeed, so matter-of-fact an inference
was this that the feat of Columbus would have
seemed less surprising in the first century of our era
than it did when actually performed in the fifteenth
century. The terrors of the great ocean held the mariner
back, rather than any doubt as to where he would
arrive at the end of the voyage.
Coupled with the idea that the habitable portion of
the earth is an island, there was linked a tolerably
definite notion as to the shape of this island. This
shape Strabo likens to a military cloak. The comparison
does not seem peculiarly apt when we are told
presently that the length of the habitable earth is more
than twice its breadth. This idea, Strabo assures us,
accords with the most accurate observations "both
ancient and modern.'' These observations seemed to
show that it is not possible to live in the region close
to the equator, and that, on the other hand, the cold
temperature sharply limits the habitability of the globe
towards the north. All the civilization of antiquity
clustered about the Mediterranean, or extended off
towards the east at about the same latitude. Hence
geographers came to think of the habitable globe as
having the somewhat lenticular shape which a crude
map of these regions suggests. We have already had
occasion to see that at an earlier day Anaxagoras
was perhaps influenced in his conception of the shape
of the earth by this idea, and the constant references
of Strabo impress upon us the thought that this
long, relatively narrow area of the earth's surface
is the only one which can be conceived of as habitable.
Strabo had much to tell us concerning zones, which,
following Posidonius, he believes to have been first
described by Parmenides. We may note, however,
that other traditions assert that both Thales and
Pythagoras had divided the earth into zones. The number
of zones accepted by Strabo is five, and he
criticises Polybius for making the number six.
The five zones accepted by Strabo are as follows: the
uninhabitable torrid zone lying in the region of the
equator; a zone on
either side of this extending to the tropic; and then
the temperate zones extending in either direction from
the tropic to the arctic regions. There seems to have
been a good deal of dispute among the scholars of the
time as to the exact arrangement of these zones, but the
general idea that the north-temperate zone is the part
of the earth with which the geographer deals seemed
clearly established. That the south-temperate zone
would also present a habitable area is an idea that is
sometimes suggested, though seldom or never distinctly
expressed. It is probable that different opinions were
held as to this, and no direct evidence being available,
a cautiously scientific geographer like Strabo would
naturally avoid the expression of an opinion regarding
it. Indeed, his own words leave us somewhat in
doubt as to the precise character of his notion regarding
the zones. Perhaps we shall do best to quote
them:
"Let the earth be supposed to consist of five zones.
(1) The equatorial circle described around it. (2) Another
parallel to this, and defining the frigid zone of the
northern hemisphere. (3) A circle passing through
the poles and cutting the two preceding circles at right-angles. The northern hemisphere contains two quarters
of the earth, which are bounded by the equator
and circle passing through the poles. Each of these
quarters should be supposed to contain a four-sided
district, its northern side being of one-half of the parallel
next the pole, its southern by the half of the equator,
and its remaining sides by two segments of the circle
drawn through the poles, opposite to each other, and
equal in length. In one of these (which of them is of
no consequence) the earth which we inhabit is situated,
surrounded by a sea and similar to an island. This,
as we said before, is evident both to our senses and to
our reason. But let any one doubt this, it makes no
difference so far as geography is concerned whether you
believe the portion of the earth which we inhabit to be
an island or only admit what we know from experience
—namely, that whether you start from the east or the
west you may sail all around it. Certain intermediate
spaces may have been left (unexplored), but these are
as likely to be occupied by sea as uninhabited land.
The object of the geographer is to describe known
countries. Those which are unknown he passes over
equally with those beyond the limits of the inhabited
earth. It will, therefore, be sufficient for describing
the contour of the island we have been speaking of, if we
join by a right line the outmost points which, up to this
time, have been explored by voyagers along the coast
on either side.''
[71]
We may pass over the specific criticisms of Strabo
upon various explorations that seem to have been of
great interest to his contemporaries, including an
alleged trip of one Eudoxus out into the Atlantic, and
the journeyings of Pytheas in the far north. It is
Pytheas, we may add, who was cited by Hipparchus
as having made the mistaken observation that the
length of the shadow of the gnomon is the same at
Marseilles and Byzantium, hence that these two places
are on the same parallel. Modern commentators have
defended Pytheas as regards this observation, claiming
that it was Hipparchus and not Pytheas who made the
second observation from which the faulty induction
was drawn. The point is of no great significance,
however, except as showing that a correct method of
determining the problems of latitude had thus early
been suggested. That faulty observations and faulty
application of the correct principle should have been
made is not surprising. Neither need we concern
ourselves with the details as to the geographical distances,
which Strabo found so worthy of criticism and
controversy. But in leaving the great geographer
we may emphasize his point of view and that of his
contemporaries by quoting three fundamental principles
which he reiterates as being among the "facts
established by natural philosophers.'' He tells us
that "(1) The earth and heavens are spheroidal. (2)
The tendency of all bodies having weight is towards a
centre. (3) Further, the earth being spheroidal and
having the same centre as the heavens, is motionless, as
well as the axis that passes through both it and the
heavens. The heavens turn round both the earth and
its axis, from east to west. The fixed stars turn round
with it at the same rate as the whole. These fixed
stars follow in their course parallel circles, the principal
of which are the equator, two tropics, and the arctic
circles; while the planets, the sun, and the moon describe
certain circles comprehended within the zodiac.''
[72]
Here, then, is a curious mingling of truth and error.
The Pythagorean doctrine that the earth is round had
become a commonplace, but it would appear that the
theory of Aristarchus, according to which the earth
is in motion, has been almost absolutely forgotten.
Strabo does not so much as refer to it; neither, as we
shall see, is it treated with greater respect by the other
writers of the period.