that time the sky is cloudless.

The effect of these desert whirlwinds is most curious, as their
force is sufficient to raise dense columns of sand and dust
several thousand feet high; these are not the evanescent
creations of a changing wind, but they frequently exist for many
hours, and travel forward, or more usually in circles, resembling
in the distance solid pillars of sand. The Arab superstition
invests these appearances with the supernatural, and the
mysterious sand-column of the desert wandering in its burning
solitude, is an evil spirit, a "Gin" ("genii" plural, of the
Arabian Nights). I have frequently seen many such columns at the
same time in the boundless desert, all travelling or waltzing in
various directions at the wilful choice of each whirlwind: this
vagrancy of character is an undoubted proof to the Arab mind of
their independent and diabolical origin.

The Abyssinian traveller, Bruce, appears to have entertained a
peculiar dread of the dangers of such sand columns, but on this
point his fear was exaggerated. Cases may have occurred where
caravans have been suffocated by whirlwinds of sand, but these
are rare exceptions, and the usual effects of the dust storm are
the unroofing of thatched huts, the destruction of a few date
palms, and the disagreeable amount of sand that not only half
chokes both man and beast, but buries all objects that may be
lying on the ground some inches deep in dust.

The wind at this season (June) was changeable, and strong blasts
from the south were the harbingers of the approaching rainy
season. We had no time to lose, and we accordingly arranged to