292 PHYSICAL GEOGRAPHY. 



zontality to the base of the mountains, and which must there- 

 fore have been deposited subsequently to the strata which 

 are inclined. ( 357 ) The ridges of the crust of the earth, 

 which are of the same geological age, appear to follow a com- 

 mon direction. The line of strike of the uplifted strata is not 

 always parallel to the axis of the chain, but sometimes inter- 

 sects it; whence I am led to infer, ( 358 ) that the pheno- 

 menon of the inclining of the strata, or of the disturbance of 

 their horizontality (which sometimes extends to the adjacent 

 plain), must, in such cases, be older than the elevation of the 

 mountains. The general direction of the land of the European 

 continent is from south-west to north-east, and is at right 

 angles to the direction of the great fissures, which is from 

 north-west to south-east, extending from the mouths of the 

 Ehine and the Elbe through the Adriatic and Bed Seas, 

 and the mountain system of Puschti-koh in Louristan, and 

 terminating in the Persian Gulf and Indian Ocean. This 

 rectangular intersection of the continent, in the direction of 

 its principal extent, has powerfully influenced the commer- 

 cial relations of Europe with Asia and the north of Africa, 

 as well as the progress of civilization on the formerly more 

 flourishing shores of the Mediterranean. ( 359 ) 



The more the imagination and the intellect are impressed 

 by lofty and massive mountain chains, from the evidences 

 they afford of great terrestrial revolutions, as the boundaries 

 of different climates, as the lines of separation from whence 

 the waters flow to opposite regions, and as the sites of a 

 peculiar vegetation, the more necessary is a correct numeri- 

 cal estimation of their volume, in order to show the smallness 

 of their mass when compared either to that of the continents, or 



