Kitap 17
1.2
And here we must previously adduce the opinions of Eratosthenes. He says, that the Nile is distant from the Arabian Gulf towards the west 1000 stadia, and that it resembles (in its course) the letter N reversed. For after flowing, he says, about 2700 stadia from Meroë towards the north, it turns again to the south, and to the winter sunset, continuing its course for about 3700 stadia, when it is almost in the latitude of the places about Meroë. Then entering far into Africa, and having made another bend, it flows towards the north, a distance of 5300 stadia, to the great cataract;Genadil. and inclining a little to the east, traverses a distance of 1200 stadia to the smaller cataract at Syene,Assouan. and 5300 stadia more to the sea.Thus Eratosthenes calculated, in following the windings of the Nile, 12,900 stadia, which is 7900 stadia more than he calculated in a straight line, as he made the distance between the same points (Meroë and Syene, i. ii. c. v. § 7) to be 5000 stadia. M. Falconer suspects that there is an error in the text; but the error lies further off. I believe that it is attributable to Eratosthenes himself, and that that geographer did nothing more than convert the days’ marches into stadia. According to Pliny, Timosthenes, commander of the fleet of Ptolemy Philadelphus, and consequently anterior to Eratosthenes, said that from Syene to Meroë was a march of 60 days ; and this statement agrees tolerably well with that of Herodotus, who calculated 56 days’ march between Elephantina and Meroë, besides a small distance the extent of which he does not state. Procopius, a learned writer, estimates a day’s march at 210 stadia; and the employment of this value, in the whole course of his history, proves that it was generally adopted. Now, if we multiply 60 by 210, we shall have 12,600 stadia, and dividing 12,900 by 60, we have 215 stadia, or nearly the amount of a day’s march according to Procopius. I am therefore of opinion that Eratosthenes did nothing more than multiply 210 or 215 by the number of 60 days, furnished by Timosthenes ; and as the excessive length of 12,900 stadia could not agree with the 5000 stadia, which he had calculated in a straight line for the same interval, he imagined this great difference arose from the excessive winding course of the Nile; consequently he supposed the Nile to change frequently the direction of its course. This opinion had its influence in the construction of Ptolemy’s map, which presents to us nearly all the inflexions which Eratosthenes imagined; in calculating the intervals of positions assigned by Ptolemy along the river, we find a total of 1260 minutes; and adding about 1/6 for the small windings, we have a total of 1470 minutes, which are equal to 12,400 stadia of the module (700 to the degree) adopted by that geographer. According to this hypothesis, the distance in Strabo will be thus divided: Setting out from Meroë, the Nile runs, days. 1. 2700 stadia to the north 12.8 2. 3700 to the S. and S. W. 17.6 3. 5300 to the N. 1/4 E. 25 4. 1200 to the N. 5.7 61.1 which nearly corresponds with the account of Timosthenes. The number of days corresponds tolerably well with the distance given by the explorers sent by Nero for the discovery of Meroë: they reported the distance to be 873 miles. If we divide this number by 60, we shall have for the day’s mean march 14ċ55 Roman miles, or 11ċ64 geographical miles, which is in fact the day’s mean march, according to Major Rennell. Letronne. In carefully measuring, upon a large map of Egypt in 47 sheets, the course of the Nile through all its windings, and with the compass opened to 1000 metres, I find— metres. From the middle of Syene to Luxor in the ancient territory of Thebes 218,900 From Luxor to Becous situated at the point of the Delta 727,500 From Becous following the Damietta branch to that city 234,000 1,180,400 This measure reduced to mean degrees of the earth equals 637°25′, and represents 5312 stadia of 500 (to the degree). I certainly did not expect to find such an agreement between the new and the ancient measures. The periodic rising of the Nile, I think, must have produced, since the time of Eratosthenes, some partial changes in the windings of the river; but we must acknowledge that these changes, for greater or for less, compensate one another on the whole. We observe, moreover, as I have already often observed, that the use of the stadium of 500 to the degree is anterior to the Alexandrine school; for at the time of Eratosthenes the stadium of 700 was more particularly made use of in Egypt. Gossellin.
