Broad and striking as were the features of the landscape over which the eye wandered from the summit of this hill, I have much difficulty in describing them.

Immediately beneath was the low region from which we had just ascended, occupying the line of the horizon from the north-east point, southwards, round to the west.  Southward, and for some degrees on either side, a fine dark line met the sky; but to the north-east and south-west was a boundless extent of earthy plain.  Here and there a solitary clump of trees appeared, and on the plain, at the distance of a mile to the eastward, were two moving specks, in the shape of native women gathering roots, but they saw us not, neither did we disturb them,—­their presence indicated that even these gloomy and forbidding regions were not altogether uninhabited.

As the reader will, I have no doubt, remember, the sandy ridges on the S.E. side of the Desert were running at an angle of about 18 degrees to the west of north, having gradually changed from the original direction of about 6 degrees to the eastward of that point.  I myself had marked this gradual change with great interest, because it was strongly corroborative of my views as to the course the current I have supposed to have swept over the central parts of the continent must have taken, i. e. a course at right angles to the ridges.  It is a remarkable fact that here, on the northern side of the Desert, and after an open interval of more than 50 miles, the same sand ridges should occur, running in parallel lines at the same angle as before, into the very heart of the interior, as if they absolutely were never to terminate.  Here, on both sides of us, to the eastward and to the westward, they followed each other like the waves of the sea in endless succession, suddenly terminating as I have already observed on the vast plain into which they ran.  What, I will ask, was I to conclude from these facts?—­that the winds had formed these remarkable accumulations of sand, as straight as an arrow lying on the ground without a break in them for more than ninety miles at a stretch, and which we had already followed up for hundreds of miles, that is to say across six degrees of latitude?  No! winds may indeed have assisted in shaping their outlines, but I cannot think, that these constituted the originating cause of their formation.  They exhibit a regularity that water alone could have given, and to water, I believe, they plainly owe their first existence.  It struck me then, and calmer reflection confirms the impression, that the whole of the low interior I had traversed was formerly a sea-bed, since raised from its sub-marine position by natural though hidden causes; that when this process of elevation so changed the state of things, as to make a continuous continent of that, which had been an archipelago of islands, a current would have passed across the central parts of it, the direction of which must have been parallel to the sandy ridges, and consequently from