7. Further, the length of the inhabited earth is measured on a line parallel with the equator, as it is in this direction that its greatest length lies: in the same way with respect to each of the continents, we must take their length as it lies between two meridians. The measure of these lengths consists of a certain number of stadia, which we obtain either by going over the places themselves, or roads or ways parallel thereto. Polybius abandons this method, and adopts the new way of taking the segment of the northern semicircle comprised between the summer rising and the equinoctial rising. But no one ought to calculate by variable rules or measures in determining the length of fixed distances: nor yet should he make use of the phenomena of the heavens, which appear different when observed from different points, for distances which have their length determined by themselves and remain unchanged. The length of a country never varies, but depends upon itself; whereas, the equinoctial rising and setting, and the summer and winter rising and setting, depend not on themselves, but on our position [with respect to them]. As we shift from place to place, the equinoctial rising and setting, and the winter and summer rising and setting, shift with us; but the length of a continent always remains the same. To make the Don and the Nile the bounds of these continents, is nothing out of the way, but it is something strange to employ for this purpose the equinoctial rising and the summer rising.
8. Of the many promontories formed by Europe, a better description is given by Polybius than by Eratosthenes; but even his is not sufficient. Eratosthenes only names three; one at the Pillars of Hercules, where Iberia is situated; a second at the Strait of Sicily, and containing Italy; the third terminated by the Cape of Malea,694 comprising all the countries situated between the Adriatic, the Euxine, and the Don. The two former of these Polybius describes in the same manner as Eratosthenes, but the third, which is equally terminated by the Cape of Malea695 and Cape Sunium,696 [he makes to] comprehend the whole of Greece, Illyria, and some portion of Thrace. [He supposes] a fourth, containing the Thracian Chersonesus and the countries contiguous to the Strait,697 betwixt Sestos and Abydos. This is occupied by the Thracians. Also a fifth, about the Kimmerian Bosphorus and the mouth of the Mæotis. Let us allow [to Polybius] his two former [promontories], they are clearly distinguished by unmistakeable bays; the first by the bay between Calpé698 and the Sacred Promontory699 where Gades700 is situated, as also by the sea between the Pillars and Sicily; the second701 by the latter sea and the Adriatic,702 although it may be objected that the extremity of Iapygia,703 being a promontory in itself, causes Italy to have a double cape. But as for the remaining [promontories of Polybius], they are plainly much more irregular, and composed of many parts, and require some other division. So likewise his plan of dividing [Europe] into six parts, similar to that of the promontories, is liable to objection.
However, we will set to rights each of these errors separately, as we meet with them, as well as the other blunders into which he has fallen in his description of Europe, and the journey round Africa. For the present we think that we have sufficiently dwelt on those of our predecessors whom we have thought proper to introduce as testimonies in our behalf, that both in the matter of correction and addition we had ample cause to undertake the present work.
CHAPTER V.
1. After these criticisms on the writers who have preceded us, we must now confine our attention to the fulfilment of our promise. We start with a maxim we laid down at the commencement, that whoever undertakes to write a Chorography, should receive as axioms certain physical and mathematical propositions, and frame the rest of his work in accordance with, and in full reliance on, these principles. We have already stated [our opinion], that neither builder nor architect could build house or city properly and as it ought to be, unless acquainted with the clima of the place, its position in respect to celestial appearances, its shape, magnitude, degree of heat and cold, and similar facts; much less should he [be without such information] who undertakes to describe the situation of the various regions of the inhabited earth.
Represent to the mind on one and the same plane-surface Iberia and India with the intermediate countries, and define likewise the west, the east, and the south, which are common to every country. To a man already acquainted with the arrangement and motions of the heavens, and aware that in reality the surface of the earth is spherical, although here for the sake of illustration represented as a plane, this will give a sufficiently exact idea of the geographical [position of the various countries], but not to one who is unacquainted with those matters. The tourist travelling over vast plains like those of Babylon, or journeying by sea, may fancy that the whole country stretched before, behind, and on either side of him is a plane-surface; he may be unacquainted with the counter-indications of the celestial phenomena, and with the motions and appearance of the sun and stars, in respect to us. But such facts as these should ever be present to the mind of those who compose Geographies. The traveller, whether by sea or land, is directed by certain common appearances, which answer equally for the direction both of the unlearned and of the man of the world. Ignorant of astronomy, and unacquainted with the varied aspect of the heavens, he beholds the sun rise and set, and attain the meridian, but without considering how this takes place. Such knowledge could not aid the object he has in view, any more than to know whether the country he chances to be in may be under the same latitude as his own or not. Even should he bestow a slight attention to the subject, on all mathematical points he will adopt the opinions of the place; and every country has certain mistaken views of these matters. But it is not for any particular nation, nor for the man of the world who cares nothing for abstract mathematics, still less is it for the reaper or ditcher, that the geographer labours; but it is for him who is convinced that the earth is such as mathematicians declare it to be, and who admits every other fact resulting from this hypothesis. He requests that those who approach him shall have already settled this in their minds as a fact, that they may be able to lend their whole attention to other points. He will advance nothing which is not a consequence of these primary facts; therefore those who hear him, if they have a knowledge of mathematics, will readily be able to turn his instructions to account; for those who are destitute of this information he does not pretend to expound Geography.
2. Those who write on the science of Geography should trust entirely for the arrangement of the subject they are engaged on to the geometers, who have measured the whole earth; they in their turn to astronomers; and these again to natural philosophers. Now natural philosophy is one of the perfect sciences.704
The “perfect sciences” they define as those which, depending on no external hypothesis, have their origin, and the evidence of their propositions, in themselves. Here are a few of the facts established by natural philosophers.705
The earth and heavens are spheroidal.
The tendency of all bodies having weight, is to a centre.
Further, the earth being spheroidal, and having the same centre as the heavens, is motionless, as well as the axis which 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.706 These fixed stars follow in their course parallel circles; the principal of which are, the equator, the two tropics, and the arctic circles. While the planets, the sun, and the moon, describe certain oblique circles comprehended within the zodiac. Admitting these points in whole or in part, astronomers