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