'Gazetteer of Arabia Vol. II' [‎1334] (389/688)

1334
NAFtD
In the restricted sense in which it is employed in the present article, the name Nafud
refers to the huge wilderness of sand which forms a counterpart in northern Central
Arabia to the Ruba'-al-Khali of the south.
Extent. —'The boundaries of the Nafud or Great Northern Desert have not yet been
ascertained with any completeness, and its extent is consequently uncertain. On
the west it commences between Taima and Jauf-al-'Umr, probably not far to the
west of a line joining those two places. The northern boundary of the Nafud runs
thence in a curve almost to the edge of the Jauf-al-'Umr depression and from there to
a point 50 miles north of Shamah, while the southern boundary, after passing a little
to the north-east of Taima, continues by the northern extremity of Jaba'al Irn5ri
Jabal Misma', and Jabal 'Aja to a place about 10 miles south of Shamah. It follows
that the breadth of the Nafud, which to the south of Jauf-al-'Umr, is 200 miles, has near
ShSmah diminished to about 60 ; but the precise limits of this portion are difficult to fix
as it is broken up and interspersed with stony ground. The districts which border the
Nafud on its northern side are, from west to east, Jauf-al-'Umr, and its connected
villages, the Hamad or Syrian desert, especially the tract known as Wadyan, and the
region of Hajarah. On the south are the districts of Jabal Shammar and Qasim.
Physical characferisti:s. —The surface of the Nafud is generally devoid of prominent
features. Its level above the sea varies, however, within considerable limits; and on
the line between Jauf-al-'Umr and Hail differences of several hundred feet in elevation
apparently occur; the central portion of the tract upon this section stands somewhat
higher than either of the margins. It is generally agreed that the north-western
part of the Nafud towards Jauf-al-'Umr is that which has the most broken and irre-
gular surface; and here the ridges and valleys of which it consists, if they have any
general direction at all, run from west to east. Nearer to Hail the Nafud consists of
open concave plains, interrupted here and there by banks of sandstone; there are also
sandhills of less height but greater circuit than those in the north. Further to the east
the Nafud falls away into low sand ridges branching out from the higher western
grounds: enclosed between these ridges are long but shallow valleys which descend
eastwards. The average altitude of the Nafud between Jauf and Hail seems to be
rather more than 3,000 feet; in a line between Hail and Najaf it is, apparently, some
700 feet less.
The Nafud throughout is composed of a bright red sand, somewhat coarse but abso
lutely pure ; this sand is almost crimson when damp and does not seem to vary in colour
or consistency from one place to another. In occasional deep depressions a firm bottom
of clay or a calcareous, flinty or quartzy stratum is exposed at the lowest point. The
Arabs state that the "sand of the Nafud is in most parts too deep and too loose to admit
of the sinking of wells.
The most remarkable phenomenon of the Nafud is a species of large depression called
a Ga'rah, or Falj. In shape it is semi-oval and resembles the print of a gigantic horse-
hoof ; the toe is the deepest part and points to the north-west, in the western Nafud but
in the eastern Nafud the direction is south, while the floor of the hollow rises south-
eastwards and reaches the ground level at the heel; the internal walls are inclined at
an angle of 50 or 60 degress to the horizon. The Falj ts of all sizes, varying in area
from I to 200 acres, but the average diameter is 300 to 400 yards and the ordinary
depth from 150 to 250 feet. The formation of these hollows is generally ascribed to
the agency An office of the East India Company and, later, of the British Raj, headed by an agent. of the prevalent winds, but this theory cannot yet be regarded as fully
established. Peculiar facts relating to these depressions are that, in spite of the
instability of their sandy sides, they apparently remain constant in shape and size from
year to year and even from generation to generation ; that none of them retain water
after rain ; and that they lie in irregular courses or strings from west to east. To the
north of Jubbah for the greater part of the way to Jauf-al-'Umr, there is a constant
succession of Faljs on both sides, of the road. In Nafud nomenclature sandhills, parti
cularly if (as is not uncommon) they are of crescent shape with the concave side to
the south, are styled Tu'us* (singular Ta'as); and passages or spaces between them
are called Khalul (singular Khali).
•Such is the definition obtained at Kuwait of a Ta'as: it differs somewhat from Hubcr's (Journal de Voyage
page &1).