Surrounding the head of the Hawash, separated only by the narrow valleys of denudation around its sources, are three elevated countries, all forming part of the table-land of Abyssinia, and between which, in the course of ages, this river has intruded itself by slow degrees, and is still progressing annually farther to the west. These three countries are Zingero to the south, Enarea to the west, and Shoa to the north, whilst the corresponding portions of the scarp are Gurague, Maitcha, and the ancient province of Fatagar, the more westerly portion of which is now possessed by the Soddo Gallas. This now excavated portion of Abyssinia must have been at a former period one continuous table land, and the countries of Zingero and of Shoa then could only have been separated by streams that flowed to the north into the Abi, or to the south into the Gibbee, the ancient Assabi. The same convulsion which has determined the peculiar course of the Abi, or Bruce’s Nile, seems to have influenced the direction of the encroachment of the Hawash into the limits of the plateau of Abyssinia; and also the position of the débouché of the Red Nile from its summit to the plains below. An examination of the map will show a curious correspondence between the situation of the sources of the Hawash, of the southern curve of the Abi, and of the break in the table land where that river joins the Red Nile near Fazuglo. A great geological fault seems to extend across Abyssinia in the direction of these several points, one effect of which (that of the great disintegration of the material of the rocks along its course) appears to me to have favoured the denudation observed on the eastern and western borders of this country. To this fracture I also attribute the sudden curve of the Abi to the west, after flowing nearly due south from lake Dembea; the physical barrier to its farther continuance in that direction not being a ridge of hills, or what is generally termed an anticlinal axis, but the presence of the opposite wall of the disjointed rock, which characterizes the extension of the fault across the table land. This is neither unfounded assertion nor rash conclusion, but the deliberate opinion I have formed by a careful examination of the mighty operations of nature that appear to have acted upon the surface geography of Abyssinia from the most remote ages.