Page:The geography of Strabo (1854) Volume 1.djvu/158

STRABO. BOOK n. which is the limit of the summer tropic, to Meroe, there are 5000 stadia, and thence to the parallel of the Cinnamon region, where the torrid zone commences, 3000 stadia. The whole of this distance has been measured, and it may be gone over either by sea or land ; the remaining portion to the equa- tor is, if we adopt the measure of the earth supplied by Era- tosthenes, 8800 stadia. Therefore, as 16,800 is to 8800, so is the space comprised between the tropics to the breadth of the torrid zone. If of the more recent measurements we prefer those which diminish the size of the earth, such as that adopted by Posi- donius, which is about 180,000 stadia, 1 the torrid zone will still only occupy half, or rather more than half, of the space com- prised between the tropics ; but never an equal space. [Re- specting the system of Aristotle, Posidonius farther says,] " Since it is not every latitude which has Arctic Circles, 2 and even those which do possess them have not the same, how can any one determine by them the bounds of the temperate zones, which are immutable?" Nothing however is proved [against Aristotle] from the fact that there are not Arctic Circles for every latitude, since they exist for all the inhabit- ants of the temperate zone, on whose account alone the zone receives its name of temperate. But the objection that the Arctic Circles do not remain the same for every latitude, but shift their places, is excellent. 3 3. Posidonius, who himself divides the earth into zones, tells us that " five is the number best suited for the explanation of the celestial appearances, two of these are periscii, 4 which reach from the poles to the point where the tropics serve for Arctic Circles ; two more are heteroscii, 5 which extend from 1 JFor the circumference . ' r *"vlz7 TioulTfor ' thols e who dwell under the equator, or at the poles. 3 Strabo's argument seems to be this. It matters but little that there may not be Arctic Circles for every latitude, since for the inhabitants of the temperate zone they do certainly exist, and these are the only people of whom we have any knowledge. But at the same time the objection is unanswerable, that as these circles differ in respect to various countries, it is quite impossible that they can fix uniformly the limits of the temper- ate zone. 4 The polar circles, where the shadow, in the summer season, travels all round in the twenty-four hours. 5 Those who live north and south of the tropics, or in the temperate zones, and at noon have a shadow only falling one way.