248 AGE OF THE ATLAS MOUNTAINS. 



same time. Thus the Pyrenees and Apennines, the moun* 

 tains of Dalmatia and Croatia, and the Carpathians, which 

 belong to the same system, — as may be deduced from the 

 descriptions given of them by various geologists, — are all 

 disposed parallel to an arc of a great circle, vehich passes 

 through Natchez and the mouth of the Persian Gulf. 

 Thus, whatever may have been the cause, the mountains 

 in Europe, which have issued from the earth at the same 

 period, form chains at the surface of the globe, — that is to 

 say, longitudinal projections, all parallel to a certain circle 

 of the sphere. If we suppose, as is natural, that this rule 

 may be applicable beyond the limits within which it has 

 been determined, the Alleghanies of North America, — since 

 their direction is also parallel to the great circle which 

 joins Natchez and the Persian Gulf, — would seem to be- 

 long, in respect to date, to the Pyrenean system. Elie 

 Beaumont has been able to verify the accuracy of this in- 

 ference by a careful examination of the descriptions of 

 American geologists. It would appear from this statement 

 that we might venture to conclude that the mountains of 

 Greece, the mountains situated to the north of the Eu- 

 phrates, and the chain of Gates in India, which also come 

 under this condition of parallelism already indicated, must 

 have risen, like the Alleghanies, along with the Pyrenees 

 and Apennines. If we apply this reasoning to the Atlas, 

 which we fmd to have the same general direction as the 

 Alps of Switzerland, from the Valais to Styria, and with 

 that of the Caucasus, the Balkan Mountains, and the Him- 

 ftialeh Mountains, we infer that these vast ranges, and also 

 the Atlas, may have risen at the same period. But at 

 ■what period did this elevation take place 1 This can be 

 ' answered in a general way, by remarking, that in Switzer- 

 land the principal chain of the Alps appears to have up- 

 raised all the secondary, and also the tertiary strata ; hence, 

 according to the opinion already stated, these Swiss moun- 

 tains, and consequently the Atlas and other ranges, already 

 mentioned, may have risen from below at a comparatively 

 recent period, — after the deposition of the tertiary rocks. 

 Allowing this hypothesis to be plausible, it could be show* 

 that an opinion of the ancients, — that, namely, which main 

 tains that the whole countrv between the Syrtis and tb' 



