Note 173 — Chapter I · THE CONTRIBUTION OF THE ANCIENT WORLD

Pliny says (Hist. nat., II, 108) that the distance from the southernmost limits of the habitable world to Meroë in Ethiopia is 1000 Roman miles and that the distance by river from Syene, on the tropic, to Meroë was found by an expedition sent out by Nero to be 871 miles. If we make this arbitrarily 700 miles in order to take into account the windings of the river, we get a total of 1700 miles. In the same passage Pliny states that Eratosthenes found the circumference of the earth to be 252,000 stades, or 31,500 Roman miles. The 1700 miles which represent the distance south of the tropic at which Pliny places the Ethiopian Ocean are therefore equivalent to 13,600 stades, and these, in turn, to 19³⁄₇° (see 378above, note 169, for method of calculating this figure). The southern limit of the oikoumene thus falls at about latitude 4° N. (23½°–19³⁄₇°).