COMMERCE. 
507 
The milk of the camel, with barley meal or Indian 
corn, and a few dates, forms the general food of 
the members of the caravan. The more opulent, 
however, have dried flesh and coffee for their pri- 
vate use. Water is carried in goat skins covered 
with tar, which, however, is often insufficient to 
prevent its evaporating. At each of the oases, 
or watered spots, which occur at distant intervals 
along the sandy waste, a stay of several days is 
made for refreshment, and for taking in a supply 
of water. The most dreadful calamity to which 
a caravan is liable, is when, from severe drought, 
one of these springs happens to be dried up. 
From this cause it is said, that, in 1798, a cara- 
van of two thousand men, with eighteen hundred 
camels, entirely perished.* Another source of 
destruction has been supposed to arise from the 
clouds of moving sand, which sweep occasionally 
over the surface of this immense plain. Mr 
Browne, however, is of opinion, that these are 
never of such density as that a caravan can be 
buried beneath them ; and that the appearance 
of such a catastrophe is produced merely by the 
sand accumulating over the bodies of men and 
animals, which have perished from other causes.t 
Cairo sends three caravans into the interior of 
* Jackson's account of the Empire of Morocco, p. 242. 
t Travels, Ch. IV. 
