172 
i 
The speed of dromedaries is generally more than a 
league an hour. We made them trot occasionally, but 
my strength could not sustain the violence of their 
movements. At midnight, finding myself extremely 
fatigued, as much on account of the jolting of the ani- 
mal, as the inconvenience of a wooden saddle without 
stirrups, I was obliged to slacken the pace a little. At 
four in the morning we were in an E. | N. E. direc- 
tion, between small mountains, which seemed almost 
to close as we advanced. 
At a quarter past six, we halted in a valley, which I 
judged to be 15 or 16 leagues from Jenboa. 
We were surrounded with mountains of different 
forms, but entirely naked. Although there was no water 
in the valley, I perceived some pretty though small 
plants, which I gathered, and among others a superb 
species of solanum, with large flowers. I found myself 
still unwell. I had been seized with two violent sick- 
nesses upon the road, before day break. 
The same day, the 1st of April, at about half- past 
two, vve continued our march in an easterly direction, 
over the same desert, through a valley of a singular ap- 
pearance. The mountains upon the south side are com- 
posed of loose sand, perfectly white; those ftpon the 
north, of rocks of porphyry, horn stone, and schistus. 
The valley is at most six hundred feet broad. When I 
saw these mountains of sand, as high as those of the 
rocks, I could not forbear admiring the force which 
heaped them up, and which binds this accumulation of 
moving sand, which forms the mountains on the south, 
so that the winds do not carry a single atom to those 
on the north. The bottom of the valley is composed of 
a variety of rocks and sand. There are several fine plants 
fe> be seen. The mountains on the north contain a fine 
