86 ON THE REVOLUTIONS OF 



makes nearly equal to that of the Euxine * was expressed in less ambi- 

 guous terms, and if we clearly knew what he meant by the Gerrhus t» 

 we should find there also strong proofs of the changes produced by the 

 rivers, and the rapidity with which they are effected ; for the alluvial 

 deposites of the river could alone J during this epoch, that is, for two 

 thousand two or three hundred years, have reduced the sea of Azof to 

 its present size, have closed the course of the Gerrhus, or that branch 

 of the Dnieper which would have united with the Hypacyris, and with 

 that river have thrown its waters into the gulph Carcinites or Olu- 

 Deignitz, and have reduced the Hypacyris itself to nearly nothing §. 

 We should have proof no less powerful if it were ascertained that the 

 Oxus or Sihoun, which now disembogues itself into the lake Aral, fell 

 once into the Caspian seaj but we have close at hand proofs sufficiently 

 convincing without being compelled to have recourse to any in the 

 least ambiguous, or to make the geographical ignorance of the ancients 

 any grounds for our physical proposition ||. 



Progress of the Downs. 

 We have already spoken of the downs or those sand heaps which 

 the sea throws on flat shores when its bottom is sandy. Wherever 

 the industry of man has failed in confining them, these downs advance 

 inland as irresistibly as the alluvial deposites of rivers advance towards 

 the sea; they drive before them pools formed by the rain-water of the 



* Melpom. lxxxvi. t Ibid. lvi. 



X This supposed diminution of the Black Sea and the sea of Azof has been attri- 

 buted to the breaking up of the Bosphorus, which happened at the pretended epoch 

 of the deluge of Deucalion; and yet, to establish the fact, recourse is had to the suc- 

 cessive diminutions of the extent assigned to these seas in Herodotus, Strabo, &c. 

 But, it is quite plain, that, if this diminution had arisen from the rupture of the 

 Bosphorus, it must have been completed long before the time of Herodotus, and 

 even the period called that of Deucalion. 



§ See Rennel's Geography of^Herodotus, p. 56, &c, and a part of M. Dureau de 

 Lamalle's work, called 'The Physical Geography of the Black Sea,' &c. At 

 present there is only the very small river of Kamennoipost, which can represent the 

 Gerrhus of Hypacyris of Herodotus. 



M. Dureau, p. 170, attributes to Herodotus the making the Borysthenes and Hy- 

 panis discharge their waters into the Palus Mceotis; but Herodotus only says 

 (Melp. liii.) that these two rivers flow together on to the same lake, that is, Liman, as 

 at present. He does not carry the Gerrhus and Hypacyris further. 



|| For instance, M. Dureau de Lamalle, in his ' Physical Geography of the Black 

 Sea." quotes Aristotle (Meteor, lib. 1. c. 13) as " telling us that in his time there 

 were many ancients, periods and peripli, proving that there was a canal leading from 

 the Caspian Sea to the Palus Moeotis." But Aristotle says in the passage in question, 

 (ed. de Duval, i. p. 545) " From the Paropamisus, amongst other rivers, descend 

 the Bactrus, the Choaspes, and Araxes, whence the Tanais, a branch of it, takes its 

 rise into the Palus Moeotis." Who cannot see that this blunder, founded neither on 

 periods nor peripli, was only the wild ideas of Alexander's soldiery, who took the 

 Jaxartes or Tanais of the Transoxian for the Don or Tanais of Scythia? Arrian and 

 Pliny distinguish them; but this was not the case in Aristotle's time. How then 

 can geological arguments be derived from such geographers? 



