Page:The journal of the Royal Geographic Society of London. Volume 34, 1864. (IA s572id13663720).pdf/327

Rh streaks—rivers one might almost call them—of loose and deep sand, generally heaped up in enormous ridges or waves, whose invariable direction is from north to south: little or no vegetation presents itself on the unstable surface.

Wallin, who was unable to push his journey on to the centre and the south, gives many ingenious conjectures about the origin, course, number, and extent of these vast sand-tracks, along with an accurate and detailed account of such portions as he was acquainted with. But the circumstances of his journey obliging him to stop short of the real origin of the “Nefood,” he could not sufficiently explain the phenomena about which he offers his interesting speculations.

But when we carry our investigations further southward, we become readily aware of the real character of this tract. The fact is, that these sandy rivers, the “Nefood,” are nothing else than inlets, branches one might say, of the great southern sand-desert, which to the south-west, south, and east, holds the place of the stonier northern desert already described, and thus completes the investing circle of Arabia. This is the “Dahna,” or “Fire-red,” as the Arabs call it; that immense mass of sand chiefly situated below lat. 23° and 22°, to the south of the Hareek and of Wadi Dowasir, whence it extends down to the Hadramaut and the neighbourhood of Aden itself. This desert throws out on the east and on the west two long arms, which run in a northerly direction till they meet the descending curve of the upper or stony desert, to which they leave barely more than one-third of the circle to complete round the central district, thus isolated from the frontiers and the coast-line. From these two main arms pus hout again several lesser branches, which constitute the “Nefood ” themselves, whose transverse lines penetrate far into the steppes of Middle Arabia, nay, in some places almost intersect them. But the subject merits a somewhat ampler detail, from the great light it throws on Arabian geography.

I have just said that the “Dahna,” or Great Southern Desert, gives out two main arms, which, passing to the east and west of the central plateau, isolate it from the coast-line, and ultimately join the stony desert, or deserted land, to the north.

Now, of these two branches, or arms, the easterly one pushing up from the “Dahna” behind ’Oman (or ’Aaman in its Arab pronunciation, but I shall adhere to that customarily adopted by Europeans in order to avoid confusion), and thence passing close in the rear of Katar, the maritime province situated between ’Oman and Hasa, enters between the Hareek and the southern extremity of Hasa, and then proceeds nearly due north, leaving Hasa to the east, and the Hareek, the Yemamah, the ’Aared, and, lastly, Sedeyr to its west. Its average breadth is about 80 miles, though in some points,