GEOLOGY. 393 



published in Latin in two quarto volumes.* Owing to 

 the rigour with which Christians were then excluded 

 from the Holy Land of the Moslem, the observations of 

 the Danish travellers were necessarily restricted to the 

 southern provinces, and those parts of the country through 

 which Niebuhr passed in his journey from Bagdad to 

 Aleppo. Since that time Mohammedan bigotry has re- 

 laxed ; but this tolerance has not much increased the in- 

 formation of naturalists ; and a few geological remarks, 

 gleaned from the pages of Burckhardt and Ali Bey, are all 

 that have been added to the scientific treasures of the 

 northern philosophers. In collecting and arranging the 

 materials which we have drawn from these various sources, 

 we have been less anxious to follow a particular system 

 than to present the general reader with a simple and in- 

 telligible treatise on the subject. 



SECTION I. GEOLOGY. 



Mountains. It has been already stated in the descrip- 

 tion of Arabia, that the mountain-chain which traverses 

 that peninsula from north to south is a continuation of 

 Lebanon in Palestine. Passing eastward of the Dead Sea, 

 it runs towards Akaba, and from thence extends as far as 

 Yemen; in some places approaching the shore of the Ara- 

 bian Gulf, and in others being separated from it by the in- 

 tervening plain of Tehama. On the eastern side the descent 

 of this range is less by one-third than on the western, ow- 

 ing perhaps to the constant accumulation of sand ; so that 

 the great central desert is considerably elevated above the 

 level of the sea. The lofty summits, that tower to the 

 clouds when viewed from the coast, dwindle into mere 

 hills when seen from the interior. At Wady Arabah the 

 surface of the western plain is perhaps 1000 feet lower than 

 the eastern. The structure of Gebel Shera (Mount Seir) 

 is principally of calcareous rock ; there are also detached 

 pieces of basalt, and large tracts of breccia, formed of 

 sand and flint. About Mount Hor and Wady Mousa sand- 

 stone of a reddish colour prevails ; and from this all the 

 tombs and temples of Petra have been excavated. To 

 the southward it follows the whole extent of the great 

 valley. The summits of these cliffs are so irregular and 



* Flora Arabica, 4to, Hafnise. 1775. Descriptiones Animalium, 

 Ibid. 1775. 



