a' 14 AFRICAN -WANDERINGS.

as its overflow extends. The troops, on this, advanced ; and the Pascha rode backwards and forwards, to encourage the people by his presence, and called this " politica sogaier " (small policy) which art he also afterwards exercised with no little effect. The tribe of the Hallenga is by no means so savage and defiant as the Haddenda, and patiently set about delivering tribute, in a monstrous quantity of straw mats, that we found would be necessary in forming the dam (gisser).

By next morning, a lot of fallen palm-trees lay scattered about the gohr, near this spot. The dam ran from N. E. to S. W., and the main bed of the gohr was 1220 metres broad. I at once told the Pascha that it would be necessary, on the other side, where the banks somewhat rose, to dig a canal so far as to reach the water level of the Atbara, and so prevent the rushing back of the waters.

The dam was commenced by a double row of palm-trees being placed close to one another perpendicularly, while mats were extended along these on both sides, and sand thrown in between them. As soon as one set of mats were filled, another was placed above, and by this means the height of five metres was reached. To prevent the yielding of the trees, and to break the force of the water above, a slope of 45° (Arab, kerath) was given to the dam. At the rocks on the right bank, where the principal body of water seemed to rush, was thrown in an immense quantity of matting sacks filled with sand. Tlie work was from time to time urged on by drums beating, and by the Pascha's presence ; this haste was all the more necessary, as the rainy season had commenced, and might, as if by a charm, call up all growing shrubs and trees into full force, and fill at any moment the gohr, before we could oppose our first bulwark to its waters. I examined the opposite side, Avhich was covered with atle-trees, and found there an arm tliat must be filled up, as well as the main course. From the greater depth of this, and its seeming to contain when full a greater weight of water, a triple row of palms was used here. To prevent the work in the main gohr from going to nought in the tro])ical rains, I had placed above tiie dam a row of palms, sunk in the earth to half their length, and supported them also by straw mats full of sand. This was run out about 270 metres. Hardly had we got our work ready, when the rain from the Abyssinian mountains turned the