Formerly the Airahra flowed into the Barissa, and was a tributary therefore of the mighty Nile; but a singular natural operation has effected an alteration in its course, and it now flows in an opposite direction. Physical geography, I think, does not describe a similar character of country as the surface of the table land of Abyssinia presents, or the relative position it occupies in consequence with surrounding countries. These must both be treated of before I can give the reader the manner in which nature is gradually effecting what former Abyssinian monarchs threatened to do, the turning of the waters of the Nile from the direction of Egypt and the north, to the Indian Ocean and the East. A mighty operation which is most certainly going on, and which can be demonstrated, will in the end drain the northern portion of Abyssinia, by a communication being opened between the river Hawash and the Abi, or Bruce’s Nile. In this place, however, any description would fail in the effect of conveying a clear idea to the mind of the reader; but in a future page, when more familiar with the country he is now travelling over with me, I will endeavour fully to explain the manner in which this curious process of natural engineering is being carried out. We forded the Airahra a little beyond a square stone building with a thatched roof, which was pointed out to me as the water mill, that was erected by the two Armenians whom I met in Tajourah, Demetrius and Joannes. Whatever ability was displayed in the construction, but little judgment had been exercised in its situation, for it stood at the bottom of a deep valley, at the distance of two miles at least, by the circuitous and rugged road, from the town of Ankobar: whilst, on the other side, to look up the ascent of the Tchakkah would have certainly occasioned the fall behind of the cap from off the head.