"نجد الجنوبية: رحلة إلى الخرج والأفلاج والسليل ووادي الدواسر في سنة ١٩١٨." [و‎‎٢‎٨] (١٠٠/٦٠)

(
— 47 —
of low rough ridges and hills ; visibility was poor on account
of a perpetual dust haze and I never obtained a view of the
Asir mountains. To the north and north-west extends a regular
Nafudh, beyond which sections of a mountain range called
Hadhb Dawasir, noted by me from the neighbourhood of the
Shifa plain and Arq al Subai Nafadh on my journey to Taif,
could be seen at intervals. The most interesting feature of the
scene was, however, an apparently isolated mountain mass of
considerable dimensions called Raiyyaniya, which was pointed
out to me as the extreme upstream limit of Wadi Dawasir.
In the neighbourhood of Raiyyaniya, perhaps forty miles
north-west of the wadi oasis, lies, according to information
collected from all sources and sifted so far as possible, a vast
depression called Hajla bounded on the east by a broad band of
Nafudh, which, it seems to me, is not unlikely to be a continuation
of the Arq al Subai itself, being, as it is said to be, to the southern
drainage channels what the Arq is to the Wadi Subai—-namely,
an absorbent barrier seldom pierced.
The wadis of Tathlith, Bisha, and Ranya appear to run down
into the plain at some distance behind Raiyyaniya and travers
ing the intervening space along erratic courses now converging
on and now diverging from each other finally reach the hill.
From this point the first two named run round the southern end
and the last round the northern end of the barrier to empty
themselves one and all into the Hajla depression, which as a
matter of fact seldom actually receives any water at all owing
to the depredations of cultivation and sand tracts in the upper
reaches of the three streams. I think it may be accepted as
substantially correct that the three great wadis above mentioned
flowing respectively from south-west, west-south-west, and
west-north-west and draining the mountain barrier of Asir
come to a joint and final end in the Hajla of Raiyyaniya.
The Nafudh strip east of the Hajla may be anything from
ten to twenty miles thick, an inpenetrable barrier to the further
progress of floods—so at least it was thought until June, 1917,
when a terrific flood, causing widespread havoc and confusion,
came down the Tatlilith and burst through the sands into its
old channel, into Wadi Dawasir which for centuries had known
no water. The Amir of the wadi was sipping coffee in his parlour
when the news of the coming flood was brought to him. " Bring
me a cup " said he mocking " and I will drink it up '. But