No More Learning

In fact the extreme points of the two
countries lie opposite to each other, the eastern extremity to the
eastern, and the western to the western: the eastern points are situated
so close as to be within sight of each other, both at Kent and at the
mouths of the Rhine. But Pytheas tells us that the island [of Britain]
is more than 20,000 stadia in length, and that Kent is some days’ sail
from France. With regard to the locality of the Ostimii, and the
countries beyond the Rhine,[451] as far as Scythia, he is altogether
mistaken. The veracity of a writer who has been thus false in describing
countries with which we are well acquainted, should not be too much
trusted in regard to unknown places.

4. Further, Hipparchus and many others are of opinion that the parallel
of latitude of the Dnieper does not differ from that of Britain; since
that of Byzantium and Marseilles are the same. The degree of shadow from
the gnomon which Pytheas states he observed at Marseilles being exactly
equal to that which Hipparchus says he found at Byzantium; the periods
of observation being in both cases similar. [452] Now from Marseilles to
the centre of Britain is not more than 5000 stadia; and if from the
centre of Britain we advance north not more than 4000 stadia, we arrive
at a temperature in which it is scarcely possible to exist. Such indeed
is that of Ierne. [453] Consequently the far region in which Eratosthenes
places Thule must be totally uninhabitable. By what guesswork he
arrived at the conclusion that between the latitude of Thule and the
Dnieper there was a distance of 11,500 stadia I am unable to divine.

5. Eratosthenes being mistaken as to the breadth [of the habitable
earth], is necessarily wrong as to its length. The most accurate
observers, both ancient and modern, agree that the known length of the
habitable earth is more than twice its breadth. Its length I take to be
from the [eastern] extremity of India[454] to the [westernmost] point of
Spain;[455] and its breadth from [the south of] Ethiopia to the latitude
of Ierne. Eratosthenes, as we have said, reckoning its breadth from the
extremity of Ethiopia to Thule, was forced to extend its length beyond
the true limits, that he might make it more than twice as long as the
breadth he had assigned to it. He says that India, measured where it is
narrowest,[456] is 16,000 stadia to the river Indus. If measured from
its most prominent capes it extends 3000 more. [457] Thence to the
Caspian Gates, 14,000. From the Caspian Gates to the Euphrates,[458]
10,000. From the Euphrates to the Nile, 5000. [459] Thence to the
Canopic[460] mouth, 1300. From the Canopic mouth to Carthage, 13,500.
From thence to the Pillars at least 8000. Which make in all 70,800
stadia. To these [he says] should be added the curvature of Europe
beyond the Pillars of Hercules, fronting the Iberians, and inclining
west, not less than 3000 stadia, and the headlands, including that of
the Ostimii, named Cabæum,[461] and the adjoining islands, the last of
which, named Uxisama,[462] is distant, according to Pytheas, a three
days’ sail. But he added nothing to its length by enumerating these
last, viz. the headlands, including that of the Ostimii, the island of
Uxisama, and the rest; they are not situated so as affect the length of
the earth, for they all lie to the north, and belong to Keltica, not to
Iberia; indeed it seems but an invention of Pytheas. Lastly, to fall in
with the general opinion that the breadth ought not[463] to exceed half
the length, he adds to the stated measure of its length 2000 stadia
west, and as many east.

6. Further, endeavouring to support the opinion that it is in accordance
with natural philosophy to reckon the greatest dimension of the
habitable earth from east to west, he says that, according to the laws
of natural philosophy, the habitable earth ought to occupy a greater
length from east to west, than its breadth from north to south. The
temperate zone, which we have already designated as the longest zone, is
that which the mathematicians denominate a continuous circle returning
upon itself. So that if the extent of the Atlantic Ocean were not an
obstacle, we might easily pass by sea from Iberia to India,[464] still
keeping in the same parallel; the remaining portion of which parallel,
measured as above in stadia, occupies more than a third of the whole
circle: since the parallel drawn through Athens,[465] on which we have
taken the distances from India to Iberia, does not contain in the whole
200,000 stadia.

Here too his reasoning is incorrect. For this speculation respecting
the temperate zone which we inhabit, and whereof the habitable earth is
a part, devolves properly on those who make mathematics their study. But
it is not equally the province of one treating of the habitable earth.
For by this term we mean only that portion of the temperate zone where
we dwell, and with which we are acquainted. But it is quite possible
that in the temperate zone there may be two or even more habitable
earths, especially near the circle of latitude which is drawn through
Athens and the Atlantic Ocean. After this he returns to the form of the
earth, which he again declares to be spheroidal. Here he exhibits the
same churlishness we have previously pointed out, and goes on abusing
Homer in his old style. He proceeds:

7. “There has been much argument respecting the continents. Some,
considering them to be divided by the rivers Nile and Tanais,[466] have
described them as islands; while others suppose them to be peninsulas
connected by the isthmuses between the Caspian and the Euxine Seas, and
between the Erythræan Sea[467] and Ecregma. ”[468] He adds, that this
question does not appear to him to be of any practical importance, but
rather, as Democritus observed, a bone of contention for angry
litigants. Where there are no precise boundary marks, columns, or walls,
as at Colyttus and Melitè,[469] it is easy for us to say such a place is
Colyttus, and such another Melitè; but not so easy to show the exact
limits: thus disputes have frequently arisen concerning certain
districts; that, for instance, between the Argives and Lacedæmonians
concerning [the possession of] Thyrea,[470] and that between the
Athenians and Bœotians relative to Oropus. [471] Further, in giving names
to the three continents, the Greeks did not take into consideration the
whole habitable earth, but merely their own country and the land exactly
opposite, namely, Caria, which is now inhabited by the Ionians and
other neighbouring tribes. In course of time, as they advanced further
and daily became acquainted with new countries, this their division came
to be general. ”

I take this last part first, and (to use Eratosthenes’ own words, not
those of Democritus) willing to pick my bone of contention, inquire,
whether they who first made the division of the three continents were
the same persons as those who first desired to distinguish their own
land from that of the Carians opposite, or whether they were only
acquainted with Greece, Caria, and some few other adjoining countries,
and not with Europe, Asia, or Africa; but that others who followed them,
and were able to write a description of the habitable earth, were the
real authors of the division into three continents. How did he know that
these were not the men who made this division of the habitable earth?
And he who divided the earth into three parts, giving to each portion
the name of “continent,” could he not form in his mind a just idea of
that taken as a whole, which he had so parcelled out. But if indeed he
were not acquainted with the whole habitable earth, but merely made a
division of some part thereof, pray what portion of that part did he
denominate Asia, or Europe, or simply continent? Such talk is altogether
nonsense.

8. The reasoning of Eratosthenes, however, is still more absurd, when he
declares that he sees no advantage in being acquainted with the exact
boundaries of countries, and then cites the example of Colyttus and
Melitè, which prove just the contrary of his assertion. Surely if a want
of certainty respecting the boundaries of Thyrea and Oropus gave rise to
war, a knowledge of the limits of different districts must be of
practical importance. Will he tell us that the boundaries of districts,
or the limits of kingdoms, may be of some service, but when applied to
continents it is carrying the matter too far. We reply, it is of equal
consequence here. Suppose a dispute between two powerful princes, one
claiming the possession of Asia and the other of Africa, to which of
these should Egypt, I mean the country called Lower Egypt, appertain.
Will any one pass over such cases on account of their rarity? By no
means. It is acknowledged by every one that the limits of each continent
ought to be defined by some notable boundary, indicated by the
configuration of the whole habitable earth. In following out this
principle, we should not be very particular if they who determine
boundaries by the rivers leave some districts undefined, since the
rivers do not reach from sea to sea, nor leave the continents altogether
as islands.

9. At the close of the book Eratosthenes blames the system of those who
would divide all mankind into Greeks and Barbarians, and likewise those
who recommended Alexander to treat the Greeks as friends, but the
Barbarians as enemies. [472] He suggests, as a better course, to
distinguish them according to their virtues and their vices, “since
amongst the Greeks there are many worthless characters, and many highly
civilized are to be found amongst the Barbarians; witness the Indians
and Ariani,[473] or still better the Romans and Carthaginians, whose
political system is so beautifully perfect. Alexander, considering this,
disregarded the advice which had been offered him, and patronized
without distinction any man he considered to be deserving. ” But we would
inquire whether those men who thus divided the human race, abandoning
one portion to contempt, and exalting to dignity the other, were not
actuated to this because they found that on one side justice, knowledge,
and the force of reason reigned supreme, but their contraries on the
other. Alexander did not disregard the advice tendered him, but gladly
embraced and followed it, respecting the wisdom of those who gave it;
and so far from taking the opposite course, he closely pursued that
which they pointed out.




BOOK II.

SUMMARY.


In the Second Book, having proposed for discussion the [opinions]
of Eratosthenes, he examines and refutes whatever that writer may
have incorrectly said, determined, or laid down. He likewise
brings forward many statements of Hipparchus, which he disproves,
and finishes with a short exposition or synopsis of the whole
subject, namely, geographical knowledge.




CHAPTER I.


1. In the Third Book of his Geography Eratosthenes furnishes us with a
chart of the habitable earth. This he divides into two portions, by a
line running from east to west parallel to the equator. He makes the
Pillars of Hercules the boundary of this line to the west, and to the
east the farthest ridges of those mountains which bound India on the
north. From the Pillars he draws the line through the Strait of
Sicily,[474] and the southern extremities of Peloponnesus and Attica, to
Rhodes and the Gulf of Issus. [475] He says, “Through the whole of this
distance the line mentioned is drawn across the sea[476] and adjacent
continents; the whole length of the Mediterranean as far as Cilicia
extending in that direction. Thence it runs nearly in a straight line
along the whole chain of the Taurus to India. The Taurus continuing in a
straight line from the Pillars divides Asia through its whole length
into two halves, north and south. So that both the Taurus and the sea
from the Pillars hither[477] lie under the parallel of Athens. ”

2. He then declares that the ancient geographical chart wants revision;
that in it the eastern portion of the Taurus is made to run too far
north, India itself being also too much drawn in the same direction. One
proof which he offers in support of this is, that the most southern
extremities of India are under the same latitude as Meroe, as attested
by many, both from astronomical observations and the temperature of the
climate. From thence to the most northerly point by the mountains of the
Caucasus,[478] there are 15,000 stadia, according to Patrocles, a writer
whom we are bound to believe, both on account of his worth, and the vast
amount of his geographical attainments. Now since the distance from
Meroe to the parallel of Athens is nearly the same, the most northerly
points of India next to the Caucasian mountains ought to be under the
same degree of latitude.

3. But there is another method (says Eratosthenes) of proving this. The
distance from the Gulf of Issus to the Euxine, proceeding in a northerly
direction towards Amisus[479] and Sinope,[480] is about 3000 stadia,
which is as much as the supposed extent of the mountains [of the
Taurus]. [481] The traveller who directs his course from Amisus due
east,[482] arrives first at Colchis, then at the high lands by the
Hyrcanian Sea,[483] afterwards at the road leading to Bactra,[484] and
beyond to the Scythians; having the mountains always on the right. The
same line drawn through Amisus westward, crosses the Propontis and
Hellespont. From Meroe to the Hellespont there are not more than 18,000
stadia. [485] The distance is just the same from the southern extremity
of India to the land of Bactria, if we add to the 15,000 stadia of that
country the 3000 which its mountains occupy in breadth.

4. Hipparchus tries to invalidate this view of Eratosthenes, by sneering
at the proofs on which it rests. Patrocles, he says, merits little
credit, being contradicted by the two writers Deimachus and
Megasthenes, who say that the distance[486] taken from the southern
ocean, is in some places 20,000, in others 30,000 stadia; that in this
assertion they are supported by the ancient charts, and he considers it
absurd to require us to put implicit faith in Patrocles alone, when
there is so much testimony against him; or that the ancient charts
should be corrected; but rather that they should be left as they are
until we have something more certain on the subject.

5. This argument, I think, is in many instances unfounded. Eratosthenes
availed himself of the statements of many writers, although Hipparchus
alleges he was solely led by Patrocles. Who then are the authors of the
statement that the southern extremity of India is under the same
parallel as Meroe; and who are they who estimate[487] the distance from
Meroe to the parallel passing through Athens? Or who, again, were those
who asserted that the whole breadth occupied by the mountains[488] was
equal to the distance from Cilicia to Amisus? Or who made known that,
travelling from Amisus, the course lay in a straight line due east
through Colchis, the [sea of] Hyrcania, so on to Bactria, and beyond
this to the eastern ocean,[489] the mountains being always on the right
hand; and that this same line carried west in a straight line, traverses
the Propontis and the Hellespont? These things Eratosthenes advances on
the testimony of men who had been on the spot, and from the study of
those numerous memoirs which he had for reference in that noble
library[490] which Hipparchus himself acknowledges to be gigantic.

6. Besides, the credibility of Patrocles can be proved by a variety of
evidence—the princes[491] who confided to him so important trusts—the
authors who follow his statements—and those, too, who criticise them,
whose names Hipparchus has recorded. Since whenever these are refuted,
the credit of Patrocles is by so much advanced. Nor does Patrocles
appear to state any thing improbable when he says that the army of
Alexander took but a very hasty view of every thing [in India], but
Alexander himself a more exact one, causing the whole country to be
described by men well acquainted with it. Which description he says was
afterwards put into his hands by Xenocles the treasurer.

7. Again, in the second volume of his Commentaries, Hipparchus accuses
Eratosthenes of himself throwing discredit on the statement of
Patrocles, on account of his differing with Megasthenes, as to the
length of India on its northern side;[492] Megasthenes stating the
length at 16,000 stadia, and Patrocles at 1000 less. Being biased by a
certain Itinerary, Eratosthenes was led to reject them both on account
of this discrepancy, and to follow the Itinerary. If then merely the
difference of 1000 stadia is sufficient to cause the authority of
Patrocles to be rejected, how much more should this be the case when we
find a difference of 8000 stadia between his statement and that of two
writers who agree perfectly in theirs, that the breadth of India is
20,000 stadia, while he gives only 12,000!

8. We reply, that [Eratosthenes] did not object [to the statement of
Patrocles] merely because it differed [from that of Megasthenes], but
because the statement of this latter as to the stadia was confirmed by
the Itinerary, an authority of no mean importance. There is nothing
wonderful in this, that though a certain statement may be credible,
another may be more credible; and that while in some instances we follow
the former, in others we may dissent from it on finding a more
trustworthy guide. It is ridiculous to say that the greater the
difference of one writer from others, the less he should be trusted. On
the contrary, such a rule would be more applicable in regard to small
differences; for in little particulars the ordinary observer and the man
of great ability are equally liable to err. On the other hand, in great
matters, the ordinary run of men are more like to be deceived than the
man of superior talent, to whom consequently in such cases greater
deference is paid.

9. Generally speaking, the men who hitherto have written on the affairs
of India, were a set of liars. Deimachus holds the first place in the
list, Megasthenes comes next, while Onesicritus and Nearchus, with
others of the same class, manage to stammer out a few words [of truth].
Of this we became the more convinced whilst writing the history of
Alexander. No faith whatever can be placed in Deimachus and Megasthenes.
They coined the fables concerning men with ears large enough to sleep
in, men without any mouths, without noses, with only one eye, with
spider-legs, and with fingers bent backward. They renewed Homer’s fable
concerning the battles of the Cranes and Pygmies, and asserted the
latter to be three spans high. They told of ants digging for gold, of
Pans with wedge-shaped heads, of serpents swallowing down oxen and
stags, horns and all; meantime, as Eratosthenes has observed,
reciprocally accusing each other of falsehood. Both of these men were
sent ambassadors to Palimbothra,[493]—Megasthenes to Sandrocottus,
Deimachus to Allitrochades his son; and such are the notes of their
residence abroad, which, I know not why, they thought fit to leave.
Patrocles certainly does not resemble them; nor do any other of the
authorities consulted by Eratosthenes contain such absurdities.

10. [494]If the meridian of Rhodes and Byzantium has been rightly
determined to be the same, then that of Cilicia and Amisus has likewise
been rightly determined; many observations having proved that the lines
are parallel, and that they never impinge on each other.

11. In like manner, that the voyage from Amisus to Colchis, and the
route to the Caspian, and thence on to Bactra, are both due east, is
proved by the winds, the seasons, the fruits, and even the sun-risings.
Frequently evidence such as this, and general agreement, are more to be
relied on than the measurement taken by means of instruments. Hipparchus
himself was not wholly indebted to instruments and geometrical
calculations for his statement that the Pillars and Cilicia lie in a
direct line due east. For that part of it included between the Pillars
and the Strait of Sicily he rests entirely on the assertion of sailors.
It is therefore incorrect to say that, because we cannot exactly
determine the duration of the longest and shortest days, nor the degree
of shadow of the gnomon throughout the mountainous region between
Cilicia and India, that therefore we are unable to decide whether the
line traced obliquely on the ancient charts should or should not be
parallel, and consequently must leave it unreformed, keeping it oblique
as the ancient charts have it. For in the first place, not to determine
any thing is to leave it undetermined; and to leave a thing
undetermined, is neither to take one view of the matter nor the other:
but to agree to leave it as the ancients have, that is to take a view of
the case. It would have been more consistent with his reasoning, if he
had told us to leave Geography alone altogether, since we are similarly
unable to determine the position of the Alps, the Pyrenees, and the
mountains of Thrace,[495] Illyria,[496] and Germany. Wherefore should we
give more credit to the ancient writers than to the modern, when we call
to mind the numerous errors of their charts which have been pointed out
by Eratosthenes, and which Hipparchus has not attempted to defend.

12. But the system of Hipparchus altogether teems with difficulties.
Reflect for an instant on the following absurdity; after admitting that
the southern extremity of India is under the same degree of latitude as
Meroe, and that the distance from Meroe to the Strait of Byzantium is
about 18,000[497] stadia, he then makes the distance from the southern
extremity of India to the mountains 30,000 stadia. Since Byzantium and
Marseilles are under the same parallel of latitude, as Hipparchus tells
us they are, on the authority of Pytheas, and since Byzantium and the
Dnieper[498] have also the same meridian, as Hipparchus equally assures
us, if we take his assertion that there is a distance of 3700[499]
stadia between Byzantium and the Dnieper, there will of course be a like
difference between the latitude of Marseilles and the Dnieper. This
would make the latitude of the Dnieper identical with that of Keltica
next the Ocean; for on proceeding 3700 stadia [north of Marseilles], we
reach the ocean. [500]

13. Again, we know that the Cinnamon Country is the most southerly point
of the habitable earth. According to Hipparchus’s own statement, the
latitude of this country, which marks the commencement of the temperate
zone, and likewise of the habitable earth, is distant from the equator
about 8800 stadia. [501] And since he likewise says that from the equator
to the parallel of the Dnieper there are 34,000 stadia, there will
remain a distance of 25,200 stadia between the parallel of the Dnieper
(which is the same as that which passes over the side of Keltica next
the Ocean) to that which separates the torrid from the temperate zone.
It is said that the farthest voyages now made north of Keltica are to
Ierne,[502] which lies beyond Britain, and, on account of its extreme
cold, barely sustains life; beyond this it is thought to be
uninhabitable. Now the distance between Keltica and Ierne is estimated
at not more than 5000 stadia; so that on this view they must have
estimated the whole breadth of the habitable earth at 30,000 stadia, or
just above.

14. Let us then transport ourselves to the land opposite the Cinnamon
Country, and lying to the east under the same parallel of latitude; we
shall there find the country named Taprobane. [503] This Taprobane is
universally believed to be a large island situated in the high seas, and
lying to the south opposite India. Its length in the direction of
Ethiopia is above 5000 stadia, as they say. There are brought from
thence to the Indian markets, ivory, tortoise-shells, and other wares in
large quantities. Now if this island is broad in proportion to its
length, we cannot suppose that the whole distance,[504] inclusive of the
space which separates it from India, is less than 3000 stadia, which is
equal to the distance of the [southern] extremity of the habitable earth
from Meroe, since the [southern] extremities of India and Meroe are
under the same parallel. It is likely there are more than 3000
stadia,[505] but taking this number, if we add thereto the 30,000
stadia, which Deimachus states there are between [the southern extremity
of India] and the country of the Bactrians and Sogdians, we shall find
both of these nations lie beyond the temperate zone and habitable
earth. [506] Who will venture to affirm such to be the case, hearing, as
they must, the statement made both by ancients and moderns of the genial
climate and fertility of northern India, Hyrcania, Aria, Margiana,[507]
and Bactriana also? These countries are all equally close to the
northern side of the Taurus, Bactriana being contiguous to that part of
the chain[508] which forms the boundary of India. A country blessed with
such advantages must be very far from uninhabitable. It is said that in
Hyrcania each vine produces a metrete[509] of wine, and each fig tree 60
medimni[510] of fruit. That the grains of wheat which fall from the husk
on to the earth spring up the year following; that bee-hives are in the
trees, and the leaves flow with honey. The same may be met with in the
part of Media called Matiana,[511] and also in Sacasena and Araxena,
countries of Armenia. In these three it is not so much to be wondered
at, since they lie more to the south than Hyrcania, and surpass the rest
of the country in the beauty of their climate; but in Hyrcania it is
more remarkable. It is said that in Margiana you may frequently meet
with a vine whose stock would require two men with outstretched arms to
clasp it, and clusters of grapes two cubits long. Aria is described as
similarly fertile, the wine being still richer, and keeping perfectly
for three generations in unpitched casks. Bactriana, which adjoins Aria,
abounds in the same productions, if we except olives.

15. That there are cold regions in the high and mountainous parts of
these countries is not to be wondered at; since in the [more] southern
climates the mountains, and even the tablelands, are cold. The districts
next the Euxine, in Cappadocia, are much farther north than those
adjoining the Taurus. Bagadania, a vast plain, situated between the
mountains of Argæus[512] and Taurus, hardly produces any fruit trees,
although south of the Euxine Sea by 3000 stadia; while the territory
round Sinope,[513] Amisus,[514] and Phanarœa abounds in olives.

The Oxus,[515] which divides Bactriana from Sogdiana, is said to be of
such easy navigation that the wares of India are brought up it into the
sea of Hyrcania,[516] and thence successively by various other rivers to
the districts near the Euxine. [517]

16. Can one find any fertility to compare with this near to the Dnieper,
or that part of Keltica next the ocean,[518] where the vine either does
not grow at all, or attains no maturity. [519] However, in the more
southerly portions of these districts,[520] close to the sea, and those
next the Bosphorus,[521] the vine brings its fruit to maturity, although
the grapes are exceedingly small, and the vines are covered up all the
winter. And in the parts near the mouth of the Palus Mæotis, the frost
is so strong that a general of Mithridates defeated the barbarians here
in a cavalry engagement during the winter, and on the very same spot in
a naval fight in summer, when the ice was thawed. Eratosthenes furnishes
us with the following inscription, which he found in the temple of
Æsculapius at Panticapæeon,[522] on a brazen vase which had been broken
by the frost:—

“If any one doubts the intensity of our winter’s cold, let him believe
when he sees this vase. The priest Stratius placed it here, not because
he considered it a worthy offering to the god, but as a proof of the
severity of our winter. ”

Since therefore the provinces we have just enumerated [are so superior
in climate, that they] cannot be compared with the countries surrounding
the Bosphorus, nor even the regions of Amisus and Sinope, (for every one
will admit that they are much superior to these latter,) it would be
idle to compare them with the districts near the Borysthenes and the
north of Keltica; for we have shown that their temperature is not so low
as Amisus, Sinope, Byzantium, and Marseilles, which are universally
acknowledged to be 3700 stadia south of the Dnieper and Keltica.

17. If the followers of Deimachus add to the 30,000 stadia the distance
to Taprobane and the boundaries of the torrid zone, which cannot be
reckoned less than 4000 stadia,[523] they will then remove Bactria and
Aria from their actual localities and place them 34,000 stadia from the
torrid zone, a distance equal to that which Hipparchus states to be
between the equator and [the mouth of] the Dnieper, and the two
countries will therefore be removed 8800 stadia north of [the mouth of]
the Dnieper and Keltica; for there are reckoned to be 8800 stadia from
the equator to the parallel of latitude which separates the temperate
from the torrid zone and which crosses the Cinnamon Country. [524] We
have proved that the regions not more than 5000 stadia north of Keltica,
as far as Ierne,[525] are scarcely habitable, but their reasoning leads
to the conclusion that there is another circle fitted for the habitation
of man, although 3800 stadia north of Ierne. [526] And that Bactra is
still farther north than the mouth of the Caspian or Hyrcanian Sea,
which is distant about 6000 stadia from the recess of the Caspian and
the mountains of Armenia and Media, and which appears to be the most
northerly point of the whole coast as far as India, with a sea navigable
to India all the way, as Patrocles, who had the government of these
regions, affirms. Now Bactriana stretches 1000 stadia farther north.
Beyond this the Scythians occupy a much larger territory, bounded by the
Northern Ocean: here they dwell, though to be sure theirs is a nomade
life. But we ask how they could exist here at all, supposing even Bactra
to be beyond the limits of the habitable globe. The distance from the
Caucasus to the Northern Sea through Bactra would be rather more than
4000 stadia. [527] This being added to the number[528] of stadia north of
Ierne[529] above-mentioned, will give us the whole amount of
uninhabitable land from Ierne northward 7800 stadia, and even omitting
the 4000 stadia altogether, those parts of Bactriana next the Caucasus
will still be 3800 stadia farther north than Ierne, and 8800 farther
north than Keltica,[530] and [the mouth] of the Dnieper.

18. Hipparchus narrates that at the Dnieper and [the north of] Keltica,
during the whole of the summer nights there is one continued twilight
from sunset to sunrise, but at the winter solstice the sun never rises
more than nine cubits above the horizon. [531] He adds that this
phenomenon is yet more remarkable in regions 6300[532] stadia north of
Marseilles, (these regions he supposes to be peopled by Kelts, but I
believe are inhabited by Britons, and 2500 stadia north of Keltica,)
where the sun at the winter solstice[533] rises only six cubits above
the horizon. That at 9100[534] stadia north of Marseilles it only rises
four cubits, and not so much as three in the countries beyond, and which
I consider much farther north than Ierne. [535] However, Hipparchus, on
the authority of Pytheas, places them south of Britain, and says that
the longest day there consists only of 19 hours;[536] while in countries
where the sun rises but four cubits above the horizon, and which are
situated 9100[537] stadia north of Marseilles, the day has 18 hours.
Consequently [according to his hypothesis] the most southerly parts of
Britain must be north of these regions. They must therefore be under the
same parallel, or almost the same, as the parts of Bactriana next to the
Caucasus, which I have shown are, according to the followers of
Deimachus, 3800 stadia farther north than Ierne. [538] Now if we add this
to the number between Marseilles and Ierne, we shall get 12,500 stadia.
But who ever made known to us that, in those parts, I mean, in the
vicinity of Bactra, this was the duration of the longest day, or the
height which the sun attains in the meridian at the winter solstice? All
these things are patent to the eyes of every man, and require no
mathematical investigation; therefore they certainly would have been
mentioned by numerous writers both amongst the ancients who have left us
histories of Persia, and by the later writers too, who have carried them
down to our own time. How, too, would their fertility, which I have
described above, harmonize with such a latitude?
The facts here advanced
are sufficient to give an idea of the learned manner in which Hipparchus
attempts to controvert the reasoning of Eratosthenes by mere petitiones
principii.

19. Again, Eratosthenes wished to show the ignorance of Deimachus, and
his want of information concerning such matters, as proved by his
assertion that India lies between the autumnal equinox[539] and winter
tropic. [540] Also in his blaming Megasthenes, where he says that in the
southern parts of India the Greater and Lesser Bear are seen to set, and
the shadows to fall both ways; assuring us that such is not the case in
India. [541] These assertions, says Eratosthenes, arise from the
ignorance of Deimachus. For it is nothing else than ignorance to suppose
that the autumnal equinox is not equally distant from the tropics with
the vernal; since in both equinoxes the sun rises at the same point, and
performs a similar revolution. Further, [he continues,] the distance
from the terrestrial tropic to the equator, between which, according to
Deimachus himself, India is situated, has been proved by measurement to
be much less than 20,000 stadia, consequently his own statements prove
that my assertion is correct, and not his. For supposing India to be
twenty or thirty thousand stadia [in breadth] it could not be contained
in the given space, but if my estimate be taken it is simple enough. It
is another evidence of his want of information, to say that the two
Bears are not seen to set, or the shadows to fall both ways, in any part
of India, since 5000 stadia south of Alexandria[542] both of these
phenomena are observable. Thus reasons Eratosthenes; whom Hipparchus
again criticises in the same mistaken way. First he substitutes [in the
text of Deimachus] the summer in place of the winter tropic; then he
says that the evidence of a man ignorant of astronomy ought not to be
received in a mathematical question; as if Eratosthenes in the main had
actually been guided by the authority of Deimachus. Could he not see
that Eratosthenes had followed the general custom in regard to idle
reasoners, one means of refuting whom is to show that their arguments,
whatever they may be, go only to confirm our views.

20. It is by assuming as a fact that the southern extremity of India is
under the same parallel as Meroe, a thing affirmed and believed by most
writers, that we shall be best able to show the absurdities of the
system of Hipparchus. In the first book of his Commentaries he does not
object to this hypothesis, but in the second book he no longer admits
it; we must examine his reasons for this. He says, “when two countries
are situated under the same parallel, but separated by a great distance,
you cannot be certain that they are exactly under the same parallel,
unless the _climata_[543] of both the places are found to be similar.
Now Philo, in his account of a voyage by sea to Ethiopia, has given us
the _clima_ of Meroe. He says that at that place the sun is vertical
forty-five days before the summer solstice,[544] he also informs us of
the proportion of shadow thrown by the gnomon both at the equinoxes and
solstices. Eratosthenes agrees almost exactly with Philo. But not a
single writer, not even Eratosthenes, has informed us of the _clima_ of
India; but if it is the case, as many are inclined to believe on the
authority of Nearchus,[545] that the two Bears are seen to set in that
country, then certainly Meroe and the southern extremity of India cannot
be under the same parallel. ”[546] [Such is the reasoning of Hipparchus,
but we reply,] If Eratosthenes confirms the statement of those authors
who tell us that in India the two Bears are observed to set, how can it
be said that not a single person, not even Eratosthenes, has informed us
of any thing concerning the _clima_ of India? This is itself information
on that point. If, however, he has not confirmed this statement, let him
be exonerated from the error. Certain it is he never did confirm the
statement. Only when Deimachus affirmed that there was no place in India
from which the two Bears might be seen to set, or the shadows fall both
ways, as Megasthenes had asserted, Eratosthenes thereupon taxed him with
ignorance, regarding as absolutely false this two-fold assertion, one
half of which, namely, that concerning the shadows not falling both
ways, Hipparchus himself acknowledged to be false; for if the southern
extremity of India were not under the same parallel as Meroe, still
Hipparchus appears to have considered it south of Syene.

21. In the instances which follow, Hipparchus, treating of these
subjects, either asserts things similar to those which we have already
refuted, or takes for granted matters which are not so, or draws
improper sequences. For instance, from the computation [of Eratosthenes]
that the distance from Babylon to Thapsacus[547] is 4800 stadia, and
thence northward to the mountains of Armenia[548] 2100 stadia more, it
does not follow that, starting from the meridian of that city, the
distance to the northern mountains is above 6000 stadia. Besides,
Eratosthenes never says that the distance from Thapsacus to these
mountains is 2100 stadia, but that a part thereof has never yet been
measured; so that this argument [of Hipparchus], founded on a false
hypothesis, amounts to nothing. Nor did Eratosthenes ever assert that
Thapsacus lies more than 4500 stadia north of Babylon.

22. Again, Hipparchus, ever anxious to defend the [accuracy of the]
ancient charts, instead of fairly stating the words of Eratosthenes
concerning his third section of the habitable earth, wilfully makes him
the author of an assertion easy of disproof. For Eratosthenes, following
the opinion we before mentioned, that a line drawn from the Pillars of
Hercules across the Mediterranean, and the length of the Taurus, would
run due west and east,[549] divides, by means of this line, the
habitable earth into two portions, which he calls the northern and
southern divisions; each of these he again essays to subdivide into as
many smaller partitions as practicable, which he denominates
sections. [550] He makes India the first section of the southern part,
and Ariana[551] the second; these two countries possessing a good
outline, he has been able not only to give us an accurate statement of
their length and breadth, but an almost geometrically exact description
of their figure. He tells us that the form of India is rhomboidal, being
washed on two of its sides by the southern and eastern oceans
[respectively], which do not deeply indent its shores. The two remaining
sides are contained by its mountains and the river [Indus], so that it
presents a kind of rectilinear figure. [552] As to Ariana, he considered
three of its sides well fitted to form a parallelogram; but of the
western side he could give no regular definition, as it was inhabited by
various nations; nevertheless he attempts an idea of it by a line drawn
from the Caspian Gates[553] to the limits of Carmania, which border on
the Persian Gulf. This side he calls western, and that next the Indus
eastern, but he does not tell us they are parallel to each other;
neither does he say this of the other sides, one bounded by the
mountains, and the other by the sea; he simply calls them north and
south.

23. Having in this manner but imperfectly traced the outlines of his
second section, the third section, for various reasons, is still less
exact. The first cause has been already explained, viz. that the line
from the Caspian Gates to Carmania is not clearly defined, as the side
of the section is common both to the third and second sections.
Secondly, on account of the Persian Gulf interrupting the continuity of
the southern side, as he himself tells us, he has been obliged to take
the measured road running through Susa and Persepolis to the boundaries
of Carmania and Persia, and suppose it straight. [554] This road, which
he calls the southern side, is a little more than 9000 stadia. He does
not, however, tell us, that it runs parallel to the northern side. It is
also clear that the Euphrates, which he makes the western boundary, is
any thing but a straight line. On leaving the mountains it flows south,
but soon shifts its course to the east; it then again pursues a
southerly direction till it reaches the sea. In fact, Eratosthenes
himself acknowledges the indirect course of this river, when he compares
the shape of Mesopotamia, which is formed by the junction of the Tigris
and Euphrates, to the cushion on a rower’s bench. The western side
bounded by the Euphrates is not entirely measured; for he tells us that
he does not know the extent of the portion between Armenia and the
northern mountains,[555] as it has not been measured. By reason of these
hinderances he states that he has been only able to give a very
superficial view of the third section, and that his estimate of the
distances is borrowed from various Itineraries, some of them, according
to his own description, anonymous. Hipparchus therefore must be
considered guilty of unfairness, for criticising with geometrical
precision a work of this general nature. We ought rather to be grateful
to a person who gives us any description at all of the character of such
[unknown] places. But when he urges his geometrical objections not
against any real statement of Eratosthenes, but merely against imaginary
hypotheses of his own creation, he shows too plainly the contradictory
bent of his mind.

24. It is in this general kind of description of the third section that
Eratosthenes supposes 10,000 stadia from the Caspian Gates to the
Euphrates. This he again divides according to former admeasurements
which he found preserved. Starting from the point where the Euphrates
passes near to Thapsacus, he computes from thence to the place where
Alexander crossed the Tigris 2400 stadia. The route thence through
Gaugamela,[556] the Lycus,[557] Arbela,[558] and Ecbatana,[559] whither
Darius fled from Gaugamela to the Caspian Gates, makes up the 10,000
stadia, which is only 300 stadia too much. Such is the measure of the
northern side given by Eratosthenes, which he could not have supposed to
be parallel to the mountains, nor yet to the line drawn from the Pillars
of Hercules through Athens and Rhodes. For Thapsacus is far removed from
the mountains, and the route from Thapsacus to the Caspian Gates only
falls in with the mountains at that point. [560] Such is the boundary on
the northern side.

25. Thus, says Eratosthenes, we have given you a description of the
northern side; as for the southern, we cannot take its measure along the
sea, on account of the Persian Gulf, which intercepts [its continuity],
but from Babylon through Susa and Persepolis to the confines of Persia
and Carmania there are 9200 stadia. This he calls the southern side, but
he does not say it is parallel to the northern. The difference of length
between the northern and southern sides is caused, he tells us, by the
Euphrates, which after running south some distance shifts its course
almost due east.

26. Of the two remaining sides, he describes the western first, but
whether we are to regard it as one single straight line, or two, seems
to be undecided. He says,—From Thapsacus to Babylon, following the
course of the Euphrates, there are 4800 stadia; from thence to the mouth
of the Euphrates[561] and the city of Teredon, 3000[562] more; from
Thapsacus northward to the Gates of Armenia, having been measured, is
stated to be 1100 stadia, but the distance through Gordyæa and Armenia,
not having yet been measured, is not given. The eastern side, which
stretches lengthwise through Persia from the Red Sea towards Media and
the north, does not appear to be less than 8000 stadia, and measured
from certain headlands above 9000, the rest of the distance through
Parætacena and Media to the Caspian Gates being 3000 stadia. The rivers
Tigris and Euphrates flowing from Armenia towards the south, after
having passed the Gordyæan mountains, and having formed a great circle
which embraces the vast country of Mesopotamia, turn towards the rising
of the sun in winter and the south, particularly the Euphrates, which,
continually approaching nearer and nearer to the Tigris, passes by the
rampart of Semiramis,[563] and at about 200 stadia from the village of
Opis,[564] thence it flows through Babylon, and so discharges itself
into the Persian Gulf. Thus the figure of Mesopotamia and Babylon
resembles the cushion of a rower’s bench. —Such are the words of
Eratosthenes.

27. In the Third Section it is true he does make some mistakes, which we
shall take into consideration; but they are nothing like the amount
which Hipparchus attributes to him. However, we will examine his
objections. [In the first place,] he would have the ancient charts left
just as they are, and by no means India brought more to the south, as
Eratosthenes thinks proper. Indeed, he asserts that the very arguments
adduced by that writer only confirm him the more in his opinion. He
says, “According to Eratosthenes, the northern side of the third section
is bounded by a line of 10,000 stadia drawn from the Caspian Gates to
the Euphrates, the southern side from Babylon to the confines of
Carmania is a little more than 9000 stadia. On the western side,
following the course of the Euphrates, from Thapsacus to Babylon there
are 4800 stadia, and thence to the outlets of the river 3000 stadia
more. Northward from Thapsacus [to the Gates of Armenia] is reckoned
1100 stadia; the rest has not been measured. Now since Eratosthenes says
that the northern side of this Third Section is about 10,000 stadia, and
that the right line parallel thereto drawn from Babylon to the eastern
side is computed at just above 9000 stadia, it follows that Babylon is
not much more than 1000 stadia east of the passage of [the Euphrates]
near Thapsacus. ”

28. We answer, that if the Caspian Gates and the boundary line of
Carmania and Persia were exactly under the same meridian, and if right
lines drawn in the direction of Thapsacus and Babylon would intersect
such meridian at right angles, the inference would be just. [565] For
then the line [from the common frontier of Carmania and Persia] to
Babylon, if produced to the meridian of Thapsacus, would appear to the
eye equal, or nearly equal, to that from the Caspian Gates to Thapsacus.
Consequently, Babylon would only be east of Thapsacus in the same
proportion as the line drawn from the Caspian Gates to Thapsacus exceeds
the line drawn from the frontier of Carmania to Babylon. [566]
Eratosthenes, however, does not tell us that the line which bounds the
western coast of Ariana follows the direction of the meridian; nor yet
that a line drawn from the Caspian Gates to Thapsacus would form right
angles with the meridian of the Caspian Gates. But rather, that the line
which would form right angles with the meridian, would be one which
should follow the course of the Taurus, and with which the line drawn
from the Caspian Gates to Thapsacus would form an acute angle. Nor,
again, does he ever say that a line drawn from Carmania to Babylon would
be parallel to that drawn [from the Caspian Gates] to Thapsacus; and
even if it were parallel, this would prove nothing for the argument of
Hipparchus, since it does not form right angles with the meridian of the
Caspian Gates.

29. But taking this for granted, and proving, as he imagines, that,
according to Eratosthenes, Babylon is east of Thapsacus rather more than
1000 stadia, he draws from this false hypothesis a new argument, which
he uses to the following purpose; and says, If we suppose a right line
drawn from Thapsacus towards the south, and another from Babylon
perpendicular thereto, a right-angled triangle would be the result;
whose sides should be, 1. A line drawn from Thapsacus to Babylon; 2. A
perpendicular drawn from Babylon to the meridian of Thapsacus; 3. The
meridian line of Thapsacus. The hypotenuse of this triangle would be a
right line drawn from Thapsacus to Babylon, which he estimates at 4800
stadia. The perpendicular drawn from Babylon to the meridian of
Thapsacus is scarcely more than 1000 stadia, the same amount by which
the line drawn [from the Caspian Gates] to Thapsacus exceeds that [from
the common frontier of Carmania and Persia] to Babylon. The two sides
[of the triangle] being given, Hipparchus proceeds to find the third,
which is much greater than the perpendicular[567] aforesaid. To this he
adds the line drawn from Thapsacus northwards to the mountains of
Armenia, one part of which, according to Eratosthenes, was measured, and
found to be 1100 stadia; the other, or part unmeasured by Eratosthenes,
Hipparchus estimates to be 1000 stadia at the least: so that the two
together amount to 2100 stadia. Adding this to the [length of the] side
upon which falls the perpendicular drawn from Babylon, Hipparchus
estimated a distance of many thousand stadia from the mountains of
Armenia and the parallel of Athens to this perpendicular, which falls on
the parallel of Babylon. [568] From the parallel of Athens[569] to that
of Babylon he shows that there cannot be a greater distance than 2400
stadia, even admitting the estimate supplied by Eratosthenes himself of
the number of stadia which the entire meridian contains;[570] and that
if this be so, the mountains of Armenia and the Taurus cannot be under
the same parallel of latitude as Athens, (which is the opinion of
Eratosthenes,) but many thousand stadia to the north, as the data
supplied by that writer himself prove.

But here, for the formation of his right-angled triangle, Hipparchus not
only makes use of propositions already overturned, but assumes what was
never granted, namely, that the hypotenuse subtending his right angle,
which is the straight line from Thapsacus to Babylon, is 4800 stadia in
length. What Eratosthenes says is, that this route follows the course of
the Euphrates, and adds, that Mesopotamia and Babylon are encompassed as
it were by a great circle formed by the Euphrates and Tigris, but
principally by the former of these rivers. So that a straight line from
Thapsacus to Babylon would neither follow the course of the Euphrates,
nor yet be near so many stadia in length. Thus the argument [of
Hipparchus] is overturned. We have stated before, that supposing two
lines drawn from the Caspian Gates, one to Thapsacus, and the other to
the mountains of Armenia opposite Thapsacus, and distant therefrom,
according to Hipparchus’s own estimate, 2100 stadia at the very least,
neither of them would be parallel to each other, nor yet to that line
which, passing through Babylon, is styled by Eratosthenes the southern
side [of the third section]. As he could not inform us of the exact
length of the route by the mountains, Eratosthenes tells us the distance
between Thapsacus and the Caspian Gates; in fact, to speak in a general
way, he puts this distance in place of the other; besides, as he merely
wanted to give the length of the territory between Ariana and the
Euphrates, he was not particular to have the exact measure of either
route. To pretend that he considered the lines to be parallel to each
other, is evidently to accuse the man of more than childish ignorance,
and we dismiss the insinuation as nonsense forthwith.

30. There, however, are some instances in which one may justly accuse
Eratosthenes. There is a difference in dissecting _limb by limb_, or
merely cutting off _portions_ [indiscriminately], (for in the former you
may only separate parts having a natural outline, and distinguished by a
regular form; this the poet alludes to in the expression,

“Cutting them limb from limb;”[571]

whereas in regard to the latter this is not the case,) and we may adopt
with propriety either one or other of these plans according to the time
and necessity. So in Geography, if you enter into every detail, you may
sometimes be compelled to divide your territories into _portions_, so to
speak, but it is a more preferable way to separate them into limbs, than
into such chance pieces; for thus only you can define accurately
particular _points and boundaries_, a thing so necessary to the
geographer. When it can be done, the best way to define a country is by
the rivers, mountains, or sea; also, where possible, by the nation or
nations [who inhabit it], and by its size and configuration. However, in
default of a geometrical definition, a simple and general description
may be said always to answer the purpose. In regard to size, it is
sufficient to state the greatest length and breadth; for example, that
the habitable earth is 70,000 stadia long, and that its breadth is
scarcely half its length. [572] And as to form, to compare a country to
any geometrical or other well-known figure. For example, Sicily to a
triangle, Spain to an ox-hide, or the Peloponnesus to a plane-leaf. [573]
The larger the territory to be divided, the more general also ought its
divisions to be.

31. [In the system of Eratosthenes], the habitable earth has been
admirably divided into two parts by the Taurus and the Mediterranean
Sea, which reaches to the Pillars. On the southern side, the limits of
India have been described by a variety of methods; by its
mountains,[574] its river,[575] its seas,[576] and its name,[577] which
seems to indicate that it is inhabited only by one people. [578] It is
with justice too that he attributes to it the form of a quadrilateral or
rhomboid. Ariana is not so accurately described, on account of its
western side being interwoven with the adjacent land. Still it is pretty
well distinguished by its three other sides, which are formed by three
nearly straight lines, and also by its name, which shows it to be only
one nation. [579] As to the Third Section of Eratosthenes, it cannot be
considered to be defined or circumscribed at all; for that side of it
which is common to Ariana is but ill defined, as before remarked. The
southern side, too, is most negligently taken: it is, in fact, no
boundary to the section at all, for it passes right through its centre,
leaving entirely outside of it many of the southern portions. Nor yet
does it represent the greatest length of the section, for the northern
side is the longest. [580] Nor, lastly, can the Euphrates be its western
boundary, not even if it flowed in a right line, since its two
extremes[581] do not lie under the same meridian. How then is it the
western rather than the southern boundary? Apart from this, the distance
to the Seas of Cilicia and Syria is so inconsiderable, that there can be
no reason why he should not have enlarged the third section, so as to
include the kingdoms of Semiramis and Ninus, who are both of them known
as Syrian monarchs; the first built Babylon, which he made his royal
residence; the second Ninus,[582] the capital of Syria;[583] and the
same dialect still exists on both sides of the Euphrates. The idea of
thus dismembering so renowned a nation, and allotting its portions to
strange nations with which it had no connexion, is as peculiarly
unfortunate. Eratosthenes cannot plead that he was compelled to do this
on account of its size, for had it extended as far as the sea and the
frontiers of Arabia Felix and Egypt, even then it would not have been as
large as India, or even Ariana. It would have therefore been much better
to have enlarged the third section, making it comprehend the whole space
as far as the Sea of Syria; but if this were done, the southern side
would not be as he represents it, nor yet in a straight line, but
starting from Carmania would follow the right side of the sea-shore from
the Persian Gulf to the mouth of the Euphrates; it would then approach
the limits of Mesene[584] and Babylon, where the Isthmus commences which
separates Arabia Felix from the rest of the continent. Traversing the
Isthmus, it would continue its course to the recess of the Arabian Gulf
and Pelusium,[585] thence to the mouth of the Nile at Canopus. [586] Such
would be the southern side. The west would be traced by the sea-shore
from the [river’s] mouth at Canopus to Cilicia. [587]

32. The fourth section would consist of Arabia Felix, the Arabian Gulf,
and the whole of Egypt and Ethiopia. Its length bounded by two
meridians, one drawn through its most western point, the other through
its most eastern; and its breadth by two parallels through its most
northern and southern points. For this is the best way to describe the
extent of irregular figures, whose length and breadth cannot be
determined by their sides.

In general it is to be observed, that length and breadth are to be
understood in different ways, according as you speak of the whole or a
part. Of a whole, the greater distance is called its length, and the
lesser its breadth; of a part, that is to be considered the length which
is parallel to the length of the whole, without any regard whether it,
or that which is left for the breadth, be the greater distance. The
length of the whole habitable earth is measured from east to west by a
line drawn parallel to the equator, and its breadth from north to south
in the direction of the meridian; consequently, the length of any of the
parts ought to be portions of a line drawn parallel to the length of the
whole, and their breadth to the breadth of the whole. For, in the first
place, by this means the size of the whole habitable earth will be best
described; and secondly, the disposition and configuration of its parts,
and the manner in which one may be said to be greater or less than
another, will be made manifest by thus comparing them.

33. Eratosthenes, however, measures the length of the habitable earth by
a line which he considers straight, drawn from the Pillars of Hercules,
in the direction of the Caspian Gates and the Caucasus. The length of
the third section, by a line drawn from the Caspian Gates to Thapsacus,
and of the fourth, by one running from Thapsacus through Heroopolis to
the country surrounded by the Nile: this must necessarily be deflected
to Canopus and Alexandria, for there is the last mouth of the Nile,
which goes by the name of the Canopic[588] or Heracleotic mouth. Whether
therefore these two lengths be considered to form one straight line, or
to make an angle with Thapsacus, certain it is that neither of them is
parallel to the length of the habitable earth; this is evident from what
Eratosthenes has himself said concerning them. According to him the
length of the habitable earth is described by a right line running
through the Taurus to the Pillars of Hercules, in the direction of the
Caucasus, Rhodes, and Athens. From Rhodes to Alexandria, following the
meridian of the two cities, he says there cannot be much less than 4000
stadia,[589] consequently there must be the same difference between the
latitudes of Rhodes and Alexandria. Now the latitude of Heroopolis is
about the same as Alexandria, or rather more south. So that a line,
whether straight or broken, which intersects the parallel of Heroopolis,
Rhodes, or the Gates of the Caspian, cannot be parallel to either of
these. These lengths therefore are not properly indicated, nor are the
northern sections any better.

34. We will now return at once to Hipparchus, and see what comes next.
Continuing to palm assumptions of his own [upon Eratosthenes], he goes
on to refute, with geometrical accuracy, statements which that author
had made in a mere general way. “Eratosthenes,” he says, “estimates that
there are 6700 stadia between Babylon and the Caspian Gates, and from
Babylon to the frontiers of Carmania and Persia above 9000 stadia; this
he supposes to lie in a direct line towards the equinoctial rising,[590]
and perpendicular to the common side of his second and third sections.
Thus, according to his plan, we should have a right-angled triangle,
with the right angle next to the frontiers of Carmania, and its
hypotenuse less than one of the sides about the right angle!
Consequently Persia should be included in the second section. ”[591]

To this we reply, that the line drawn from Babylon to Carmania was
never intended as a parallel, nor yet that which divides the two
sections as a meridian, and that therefore nothing has been laid to his
charge, at all events with any just foundation. In fact, Eratosthenes
having stated the number of stadia from the Caspian Gates to Babylon as
above given,[592] [from the Caspian Gates] to Susa 4900 stadia, and from
Babylon [to Susa] 3400 stadia, Hipparchus runs away from his former
hypothesis, and says that [by drawing lines from] the Caspian Gates,
Susa, and Babylon, an obtuse-angled triangle would be the result, whose
sides should be of the length laid down, and of which Susa would form
the obtuse angle. He then argues, that “according to these premises, the
meridian drawn from the Gates of the Caspian will intersect the parallel
of Babylon and Susa 4400 stadia more to the west, than would a straight
line drawn from the Caspian to the confines of Carmania and Persia; and
that this last line, forming with the meridian of the Caspian Gates half
a right angle, would lie exactly in a direction midway between the south
and the equinoctial rising. Now as the course of the Indus is parallel
to this line, it cannot flow south on its descent from the mountains, as
Eratosthenes asserts, but in a direction lying between the south and the
equinoctial rising, as laid down in the ancient charts. ” But who is
there who will admit this to be an obtuse-angled triangle, without also
admitting that it contains a right angle? Who will agree that the line
from Babylon to Susa, which forms one side of this obtuse-angled
triangle, lies parallel, without admitting the same of the whole line as
far as Carmania? or that the line drawn from the Caspian Gates to the
frontiers of Carmania is parallel to the Indus? Nevertheless, without
this the reasoning [of Hipparchus] is worth nothing.

“Eratosthenes himself also states,” [continues Hipparchus,[593]] “that
the form of India is rhomboidal; and since the whole eastern border of
that country has a decided tendency towards the east, but more
particularly the extremest cape,[594] which lies more to the south than
any other part of the coast, the side next the Indus must be the same. ”

35. These arguments may be very geometrical, but they are not
convincing. After having himself invented these various difficulties, he
dismisses them, saying, “Had [Eratosthenes] been chargeable for small
distances only, he might have been excused; but since his mistakes
involve thousands of stadia, we cannot pardon him, more especially since
he has laid it down that at a mere distance of 400 stadia,[595] such as
that between the parallels of Athens and Rhodes, there is a sensible
variation [of latitude]. ” But these sensible variations are not all of
the same kind, the distance [involved therein] being in some instances
greater, in others less; greater, when for our estimate of the climata
we trust merely to the eye, or are guided by the vegetable productions
and the temperature of the air; less, when we employ gnomons and
dioptric instruments. Nothing is more likely than that if you measure
the parallel of Athens, or that of Rhodes and Caria, by means of a
gnomon, the difference resulting from so many stadia[596] will be
sensible. But when a geographer, in order to trace a line from west to
east, 3000 stadia broad, makes use of a chain of mountains 40,000 stadia
long, and also of a sea which extends still farther 30,000 stadia, and
farther wishing to point out the situation of the different parts of the
habitable earth relative to this line, calls some southern, others
northern, and finally lays out what he calls the sections, each section
consisting of divers countries, then we ought carefully to examine in
what acceptation he uses his terms; in what sense he says that such a
side [of any section] is the north side, and what other is the south, or
east, or west side. If he does not take pains to avoid great errors, he
deserves to be blamed, but should he be guilty merely of trifling
inaccuracies, he should be forgiven. But here nothing shows thoroughly
that Eratosthenes has committed either serious or slight errors, for on
one hand what he may have said concerning such great distances, can
never be verified by a geometrical test, and on the other, his accuser,
while endeavouring to reason like a geometrician, does not found his
arguments on any real data, but on gratuitous suppositions.

36. The fourth section Hipparchus certainly manages better, though he
still maintains the same censorious tone, and obstinacy in sticking to
his first hypotheses, or others similar. He properly objects to
Eratosthenes giving as the length of this section a line drawn from
Thapsacus to Egypt, as being similar to the case of a man who should
tell us that the diagonal of a parallelogram was its length. For
Thapsacus and the coasts of Egypt are by no means under the same
parallel of latitude, but under parallels considerably distant from each
other,[597] and a line drawn from Thapsacus to Egypt would lie in a kind
of diagonal or oblique direction between them. But he is wrong when he
expresses his surprise that Eratosthenes should dare to state the
distance between Pelusium and Thapsacus at 6000 stadia, when he says
there are above 8000. In proof of this he advances that the parallel of
Pelusium is south of that of Babylon by more than 2500 stadia, and that
according to Eratosthenes (as he supposes) the latitude of Thapsacus is
above 4800 stadia north of that of Babylon; from which Hipparchus tells
us it results that [between Thapsacus and Pelusium] there are more than
8000 stadia. But I would inquire how he can prove that Eratosthenes
supposed so great a distance between the parallels of Babylon and
Thapsacus? He says, indeed, that such is the distance from Thapsacus to
Babylon, but not that there is this distance between their parallels,
nor yet that Thapsacus and Babylon are under the same meridian. So much
the contrary, that Hipparchus has himself pointed out, that, according
to Eratosthenes, Babylon ought to be east of Thapsacus more than 2000
stadia. We have before cited the statement of Eratosthenes, that
Mesopotamia and Babylon are encircled by the Tigris and Euphrates, and
that the greater portion of the Circle is formed by this latter river,
which flowing north and south takes a turn to the east, and then,
returning to a southerly direction, discharges itself [into the sea].
So long as it flows from north to south, it may be said to follow a
southerly direction; but the turning towards the east and Babylon is a
decided deviation from the southerly direction, and it never recovers a
straight course, but forms the circuit we have mentioned above. When he
tells us that the journey from Babylon to Thapsacus is 4800 stadia, he
adds, following the course of the Euphrates, as if on purpose lest any
one should understand such to be the distance in a direct line, or
between the two parallels. If this be not granted, it is altogether a
vain attempt to show that if a right-angled triangle were constructed by
lines drawn from Pelusium and Thapsacus to the point where the parallel
of Thapsacus intercepts the meridian of Pelusium, that one of the lines
which form the right angle, and is in the direction of the meridian,
would be longer than that forming the hypotenuse drawn from Thapsacus to
Pelusium. [598] Worthless, too, is the argument in connexion with this,
being the inference from a proposition not admitted; for Eratosthenes
never asserts that from Babylon to the meridian of the Caspian Gates is
a distance of 4800 stadia. We have shown that Hipparchus deduces this
from data not admitted by Eratosthenes; but desirous to controvert every
thing advanced by that writer, he assumes that from Babylon to the line
drawn from the Caspian Gates to the mountains of Carmania, according to
Eratosthenes’ description, there are above 9000 stadia, and from thence
draws his conclusions.

37. Eratosthenes[599] cannot, therefore, be found fault with on these
grounds; what may be objected against him is as follows. When you wish
to give a general outline of size and configuration, you should devise
for yourself some rule which may be adhered to more or less. After
having laid down that the breadth of the space occupied by the mountains
which run in a direction due east, as well as by the sea which reaches
to the Pillars of Hercules, is 3000 stadia, would you pretend to
estimate different lines, which you may draw within the breadth of that
space, as one and the same line? We should be more willing to grant you
the power of doing so with respect to the lines which run parallel to
that space than with those which fall upon it; and among these latter,
rather with respect to those which fall within it than to those which
extend without it; and also rather for those which, in regard to the
shortness of their extent, would not pass out of the said space than for
those which would. And again, rather for lines of some considerable
length than for any thing very short, for the inequality of lengths is
less perceptible in great extents than the difference of configuration.
For example, if you give 3000 stadia for the breadth at the Taurus, as
well as for the sea which extends to the Pillars of Hercules, you will
form a parallelogram entirely enclosing both the mountains of the Taurus
and the sea; if you divide it in its length into several other
parallelograms, and draw first the diagonal of the great parallelogram,
and next that of each smaller parallelogram, surely the diagonal of the
great parallelogram will be regarded as a line more nearly parallel and
equal to the side forming the length of that figure than the diagonal of
any of the smaller parallelograms: and the more your lesser
parallelograms should be multiplied, the more will this become evident.
Certainly, it is in great figures that the obliquity of the diagonal and
its difference from the side forming the length are the less
perceptible, so that you would have but little scruple in taking the
diagonal as the length of the figure. But if you draw the diagonal more
inclined, so that it falls beyond both sides, or at least beyond one of
the sides, then will this no longer be the case; and this is the sense
in which we have observed, that when you attempted to draw even in a
very general way the extents of the figures, you ought to adopt some
rule. But Eratosthenes takes a line from the Caspian Gates along the
mountains, running as it were in the same parallel as far as the
Pillars, and then a second line, starting directly from the mountains to
touch Thapsacus; and again a third line from Thapsacus to the frontiers
of Egypt, occupying so great a breadth. If then in proceeding you give
the length of the two last lines [taken together] as the measure of the
length of the district, you will appear to measure the length of one of
your parallelograms by its diagonal. And if, farther, this diagonal
should consist of a broken line, as that would be which stretches from
the Caspian Gates to the embouchure of the Nile, passing by Thapsacus,
your error will appear much greater.