In obedience to these orders Lyttelton's brigade brought up their left shoulders, deployed into line, and advanced west; Maxwell's Soudanese scrambled up the Surgham rocks, and, in spite of a sharp fire, cleared the peak with the bayonet and pressed on down the further side; Lewis began to come into action on Maxwell's right; MacDonald, against whom the Khalifa's attack was at first entirely directed, remained facing south-west, and was soon shrouded in the smoke of his own musketry and artillery fire. The three brigades which were now moving west and away from the Nile attacked the right flank of the Dervishes assailing MacDonald, and, compelling them to form front towards the river, undoubtedly took much of the weight of the attack off the isolated brigade. There remained the gap between Lewis and MacDonald. But Wauchope's brigade--still in four parallel columns of route--had shouldered completely round to the north, and was now doubling swiftly across the plain to fill the unguarded space. With the exception of Wauchope's brigade and of Collinson's Egyptians, the whole infantry and artillery force were at once furiously engaged. The firing became again tremendous, and the sound was even louder than during the attack on the zeriba. As each fresh battalion was brought into line the tumult steadily increased. The three leading brigades continued to advance westward in one long line looped up over Surgham Hill, and with the right battalion held back in column. As the forces gradually drew nearer, the possibility of the Dervishes penetrating the gap between Lewis and MacDonald presented itself, and the flank battalion was wheeled into line so as to protect the right flank. The aspect of the Dervish attack was at this moment most formidable. Enormous masses of men were hurrying towards the smoke-clouds that almost hid MacDonald. Other masses turned to meet the attack which was developing on their right. Within the angle formed by the three brigades facing west and MacDonald facing nearly south a great army of not fewer than 15,000 men was enclosed, like a flock of sheep in a fold, by the thin brown lines of the British and Egyptian brigades. As the 7th Egyptians, the right battalion of Lewis's brigade and nearest the gap between that unit and MacDonald, deployed to protect the flank, they became unsteady, began to bunch and waver, and actually made several retrograde movements. There was a moment of danger; but General Hunter, who was on the spot, himself ordered the two reserve companies of the 15th Egyptians under Major Hickman to march up behind them with fixed bayonets. Their morale was thus restored and the peril averted. The advance of the three brigades continued.