206 John Hogg, Esq., on the Geography and 
he “‘ saw for the first and only ¢ime in this Peninsula volcanic 
rocks.” For a distance of about two miles, the hills pre- 
sented perpendicular cliffs, formed in semicircles, and some 
of them nearly in circles, none exceeding 60 or 80 feet in 
height ; in other places, there was an appearance of volcanic 
craters. The rock is black, with sometimes a slight red aspect, 
full of cavities, and of a rough surface. 
But near Wadi Nukb, where are some plantations of date 
trees, according to the same traveller, the land is chalky, or 
calcareous, with fossil shells imbedded, and which, doubtless, 
formerly constituted a portion of that nearly opposite in the 
north of the Isle of Tiran, and in the north-east of the Ailani- 
tic Gulf, near Ras Furtak. The separations, now occupied by 
the sea, in the Strait of Tiran, as well as in the straits be- 
tween that isle, the point near Furtak, and the smaller isle 
of Senafer, have very possibly been caused by the same (or a 
like) voleanic action, which appears to have taken place in 
raising up the basaltic rocks between Sherm and a little below 
the line of 28° north latitude. This strip of chalky limestone 
seems to lie between sandstone strata north and south, and the 
alluvial, or marine deposit, along the sea-shore on the east of it. 
After Wadi Nukb, a large sloping sandstone plain, called 
Mofassel-el-Korfa, stretches out towards Wadi Orta; over it, 
many beds of torrents, descending from the high chain of El 
Turfa, cross in their course to the Gulf of Akaba. Orta it- 
self consists of greenstone, red porphyry, and granite, the 
last species of rock succeeding in Wadi’s Chosib and Kyd. 
So also, in Wadi Melhageh (Burekhardt’s Molahdje), a narrow 
and rocky passage enclosed by high cliffs, granite alone pre- 
_vails. To the range intervening between the gulf and the 
last-named valley, as it is of a dark coloured granite, I have as- 
signed the name of the “‘ Melana (dlack) Mountains,” Mérae 
“Ogeaz of Ptolemy, rather than to those volcanic hills nearer 
Sherm, as Burckhardt has done. 
A little south of 28° 30’ north latitude is Dahab, or as Well- 
sted gives it, Mersa Dahab, signifying the “ Port of Gold,” 
which he adds, “is the only well-sheltered harbour in the 
sea.” Itis remarkable in shape, being a semicircle of marine 
formation, 7. e., of coral, on which is a layer of sand, slightly 
