After some sharp skirmishing, the advance was made to Dongola, when the English battalion was sent home disabled, and in time was replaced by a strong English brigade under General Gatacre. Early in 1897, a railroad had been thrown across the desert from Wady Haifa towards Abu Hamed, obviating the need of making an immense detour around the bend of the Nile near Dongola. The califa had, by this time, organised his defence. The Jaalin tribe had revolted against him at Metammeh, and had sought for help from the Egyptians, but before the supply of rifles arrived, the dervishes under the Emir Mahmud stormed Metammeh and annihilated the whole tribe of the Jaalin Arabs. The van of the army of invasion, both the flying corps and the flotilla of gunboats, advanced upon Abu Hamed towards the end of August. Major-General Hunter carried the place by storm. Berber was found to be deserted, and was occupied on September 5th. Hunter burned Adarama and reconnoitred on the Atbara. The gunboats bombarded Metammeh and reduced the place to ruins. The sirdar, General Kitchener, then went on a mission to Kassala, where he found the Italians anxious to evacuate. He thereupon made an agreement whereby the Egyptians should occupy the place, which was accordingly accomplished under Colonel Parsons on Christmas Day, 1897. Disagreements among the dervishes prevented them from making any concerted defence, and early in 1896 Kitchener renewed the advance and captured the dervish stores at Shendy on March 27th. The zeriba or camp of Mahmud was attacked and stormed with great loss to the dervishes on the 5th of April. On the date scheduled beforehand by Lord Kitchener, just after the annual rains had refreshed the country, the Anglo-Egyptian army made its final advance upon Khartum. There were ten thousand British troops and fifteen thousand Egyptians. The forces were concentrated at Wady Hamed, sixty miles above Omdurman, from which point they bombarded the city with shells filled with deadly lyddite, and the mosque and tomb of the late Mahdi were destroyed. At length the entire army advanced to within four miles of Khartum. On September 2nd the cavalry and a horse battery reached Kasar Shanbal. From this point they saw the whole army of the califa, consisting of from forty to fifty thousand men, advancing to confront them from behind the hills. The Anglo-Egyptians advanced to meet the dervishes disposed in the form of a horseshoe, with either end resting upon the banks of the river. At intervals along the whole line of the army were field-pieces and Maxims, and the gunboats were within reach to aid in shelling the enemy. The British soldiers then built a square sand rampart called a zarilea, and their Egyptian allies dug defensive trenches.