Geographical Notices. 375 
the level of the ocean. Its lowest depression is 900 to 1000 feet 
high, while other portions attain a height of 1800 to 2200 feet. 
After leaving the Murzuk plateau, the caravan, as it went toward 
Ghat, appears to have found a mean altitude of 1250 to 1450 
feet; and so likewise for some distance to the southward of 
Ghat, until it came to the wild mountainous region which lies 
between Ghat and Air, where it entered a Wady (Adschunscher) 
lying at a height of 2956 feet, and situated amid mountain 
_— that were roughly estimated as about 4000 feet high. 
rom Tin Tellust in Air, the altitude of the region was estima- 
ted at 1894 feet, nor can we suppose the southern Hamadah to 
he at a much greater depression. 
Though the Sahara lies at such an elevation, yet we hear of 
no very lofty mountains there: in Air, however, we come u 
a few single peaks, (the Baghtzen, Dodschen, and others,) but 
these are only from 3000 to 5000 feet in height. Nor are there 
vel | 
Europe, those of Spain and the Morea. The two other pla- 
teaus may be com a i South 
German ‘table-lands, while the deep lying Wady (600 feet) is 
about the height of the elevated at 2 of Bohemia. 
‘be a high land, it does not follow that itis so throughout. The 
probabilities of the case, however, are in favor of this conclu- 
sion. The measurements of Vogel, in the year 1853, on his 
Toute from Tripoli over Sokna to Murzuk, and thence to Bilma, 
Show that some of the eastern of 
highland. It is true that he found the tract between the base of 
Gharian and Sokna much lower than elsewhere, (Boudschem is 
only 200 : ove the lev 
of Eee Ge indels nariow pass of the Black Mountains to 
