Abu Daumah (of the "one Theban Palm"). Porphyritic trap lay on
both sides of us. To the right rose the Jebel 'Ukbal, whose grey
form (El-Ash'hab) we had seen from the heights above Umm
el-Harab: the whole range of four heads, forming the
south-western rim of the Bada saucer, is known as El-'Akabil.
Below these blocks the Wady-sides were cut into buttresses of
yellow clay, powdered white with Sabkh, or "impure salt." Charred
circlets in the sand showed where alkali had been burned: the
ashes, packed in skins, are shipped at El-Wijh for Syria, where
they serve to make soap. The Bedawin call it Aslah (Athlah); the
Egyptians Ghassalah ("the washer"), because, when rubbed in the
hands, its succulent shoots clean the skin. Camels eat it,
whereas mules refuse it, unless half-starved. This plant
apparently did not extend all up the Wady. The water, where there
is any, swings under the left bank; an ample supply had been
promised to us, with the implied condition that we should camp at
this Mahattat el-'Urban ("Halting place of the Arabs"), after a
marching day of two hours! Seeing that we rode on, the Baliyy
declared that they had searched for the two principal pools, and
that both were dry, or rather had been buried by the Bedawin.
But, with characteristic futility, they had allowed me to
overhear their conversation; and the word was passed to the
soldiers, who at once filled themselves and their water-skins.

Hitherto we had been marching south of east. Presently, where the
pretty green Wady el-Suram falls into the left bank, we turned a
corner, and sighted in front, or to the north, the great plain of
Bada. The block, El-'Akabil, had projected a loop of some ten
miles to be rounded, whereas a short cut across it would not have
exceeded three. And now the Wady Aba Daumah abruptly changed