While the army were to move along the west bank of the river--the Omdurman side--a force of Arab irregulars, formed from the friendly tribes, would march along the east bank and clear it of any Dervishes. All the debris which the Egyptian advance had broken off the Dervish Empire was thus to be hurled against that falling State. Eager for plunder, anxious to be on the winning side, Sheikhs and Emirs from every tribe in the Military Soudan had hurried, with what following the years of war had left them, to Wad Hamed. On the 26th of August the force of irregulars numbered about 2,500 men, principally Jaalin survivors, but also comprising bands and individuals of Bisharin; of Hadendoa from Suakin; of Shukria, the camel-breeders; of Batahin, who had suffered a bloody diminution at the Khalifa's hands; of Shaiggia, Gordon's vexatious allies; and lastly some Gellilab Arabs under a reputed son of Zubehr Pasha. The command of the whole motley force was given to Major Stuart-Wortley, Lieutenant Wood accompanying him as Staff Officer; and the position of these officers among the cowed and untrustworthy Arabs was one of considerable peril. While the infantry divisions were marching round the heights of Shabluka to the camp opposite Royan island, the steamers and gunboats ascended the stream and passed through the gorge, dragging up with them the whole fleet of barges and gyassas. The northern end of the narrow passage had been guarded by the five Dervish forts, which now stood deserted and dismantled. They were well built, and formed nearly a straight line--four on one bank and one on the other. Each fort had three embrasures, and might, when occupied, have been a formidable defence to the cataract. Threshing up against the current, the gunboats and stern-wheelers one after another entered the gorge. The Nile, which below is nearly a mile across, narrows to a bare 200 yards. The pace of the stream becomes more swift. Great swirls and eddies disturb its surface. High on either side rise black, broken, and precipitous cliffs, looking like piles of gigantic stones. Through and among them the flood-river pours with a loud roaring, breaking into foam and rapids wherever the submerged rocks are near the surface. Between the barren heights and the water is a strip of green bushes and grass. The bright verdant colour seems the more brilliant by contrast with the muddy water and the sombre rocks. It is a forbidding passage. A few hundred riflemen scattered Afridiwise among the tops of the hills, a few field-guns in the mud forts by the bank, and the door would be shut.