Strabo, Geography (English) (XML Header) [genre: prose] [word count] [Str.]. | ||

<<Str. 2.1.35 | Str. 2.1.37 (Greek English(2)) | >>Str. 2.1.39 |

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, ^{[Note]} 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. ^{[Note]} 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.
2.1.37

Eratosthenes ^{[Note]} 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. This is the sum of what may be alleged against Eratosthenes.

Strabo, Geography (English) (XML Header) [genre: prose] [word count] [Str.]. | ||

<<Str. 2.1.35 | Str. 2.1.37 (Greek English(2)) | >>Str. 2.1.39 |