Chap. 10.] ACCOUNT OF COUNTEIES, ETC, 413 



either that its waters are driven back by the Etesian winds \ 

 which are blowing at this season of the year from an oppo- 

 site direction, and that the sea which lies beyond is driven 

 into the mouths of the river ; or else that its waters are 

 swollen by the summer rains of ^thiopia^, wnich fall from 

 the clouds conveyed thither by the Etesian winds from 

 other parts of the earth. Timaeus the mathematician has 

 alleged a reason of an occult nature : he says that the source 

 of the river is known by the name of Phiala, and that the 

 stream buries itself in channels underground, where it sends 

 forth vapours generated by the heat among the steaming 

 rocks amid which it conceals itself; but that, during the days 

 of the inundation, in consequence of the sun approaching 

 nearer to the earth, the waters are drawn forth by the 

 influence of his heat, and on being thus exposed to the 

 air, overflow; after which, in order that it may not be 

 utterly dried up, the stream hides itself once more. He 

 says that this takes place at the rising of the Dog-Star, 

 when the sun enters the sign of Leo, and stands in a vertical 

 position over the source of the river, at which time at 

 that spot there is no shadow thrown. Most authors, however, 

 are of opinion, on the contrary, that the river flows in greater 

 volume when the sun takes his departure for the north, which 

 he does when he enters the signs of Cancer and Leo, because 

 its waters then are not dried up to so great an extent ; while 

 on the other hand, when he returns towards the south pole and 

 re-enters Capricorn, its waters are absorbed by the heat, 

 and consequently flow in less abundance. If there is 

 any one inclined to be of opinion, with Timaeus, that the 

 waters of the river may be drawn out of the earth by the 

 heat, it will be as well for him to bear in mind the fact, that 

 the absence of shadow is a phaenomenon which lasts conti- 

 nuously^ in these regions. 



^ The Etesians are periodical winds, which blow steadily from one 

 quarter for forty days each year, during the season of the Dog-days. 

 The opinion here stated was that promidgated by Thales the philosopher. 

 Seneca refutes it in B. iv. c. 2. of his Quaest. Nat. 



2 This was the opinion of Democritus of Abdera, and of Agathar- 

 chidas of Cnidos. It is combated by Diodorus Sicidus, B. i., but it is 

 the opinion most generally received at the present day. See the disqui- 

 sition on the subject introduced in the Ninth book of Lucan's Pharsaha. 



3 And that the high tide or intmdation would be consequently con- 

 tinuous as well. 



