"كتيّب الجزيرة العربية. المجلد I. ١٩١٧" [‎٩‎٧] (٧٤٨/١٠٦)

PHYSICAL CHARACTER
97
(Midian) attains a greater elevation (peaks over 8,000 feet) than
the Ridge itself. Hejaz, therefore, comprises five parallel zones :
(1) A low, sandy coastal strip (Tihamah) fringed with coral reefs
and narrowest in Midian, where, at points, the highlands fall almost
into the sea ; (2) a mountainous belt falling in elevation from N.
to S., until between Jiddah and Mecca it is hardly 2,000 feet high ;
(3) an intramontane plateau belt of great elevation in the N,, where
the lava caps of the 'Aweiridh have resisted denudation, but falling
southward to under 1,000 feet west of Mecca and Ta'if ; (4) the
main Eidge itself, highest where capped with lava, as in the Hisma,
; 'nia 'Aweiridh, and Kheibar harrahs (8,000 to 6,000 ft.), but still keeping
Gil a mean elevation of over 5,000 ft. behind Mecca ; (5) the uppermost
-aydm fringe of the eastward slope towards Central Arabia.
^ The few centres of settled population lie almost entirely in the
3peA first and third of these zones. The port settlements, Akaba, Mu-
to il weilah, Wejh, Umlejh, Yambo', Rabugh, Jiddah, and Lith, with a few
shams intermediate groups of huts, are of course in the first, and El-'Ala,
)tli tt Medina, and Mecca in the third. The only exceptions of note are
Hejai certain rare oases, which lie on the line between the fourth and
3m 1 fifth zones, Teima, Kheibar, Henakiyah, and Ta'if. The Hejaz
theli Railway, after following the western edge of the fifth zone from
)vinci Ma'an, has to cross a low part (pass of Qal'ah Dar el-Hamra,
sis, I 3,700 ft.) of the fourth zone (the £ Ridge ') between Tebuk and
to SJ Meda'in Salih in order to reach Medina. From Medina the rails
could proceed to Mecca by following the same third zone; but for
atil • several reasons, e. g. for better security from interference by nomad
> the I tribes, it has been proposed to bring them down westward into the
m-k- fi rst zone at Rabugh, and thence up behind Jiddah into the third
in and again.
of Ef big drainage channels, originating on the main Ridge, traverse
als« fhe third zone, and break through the second to the sea, all being
istia® ^ke fiuincirci type, i.e. without permanent surface flow. In the
^ mfe north (Midian), where the elevation is great and there is some
j reasi P re cipitation from the East Mediterranean area, these deep wadis
follow one another in rapid succession. They cut up the country
into a series of detached blocks, and force communications from
north to south to keep either close along the shore (Egyptian
pilgrim route) or within the fifth belt (Syrian pilgrim route and
it ^ e '' az Railway)- Nor, owing to their exceedingly steep gradients,
6 «r do they favour communication from west to east, or create fertility.
)ia , Midian, therefore, is a conspicuously ill-inhabited, unsettled, and
op 1 ' unknown district in a peninsula to almost all parts of which these
:tl#f epithets apply in varying degrees.
AEABIA I ,,