The advance was made by the two brigades in squares marching in echelon. Owing to some slight delay in getting the 1st Brigade forward, the 2nd (which General Graham and his staff now joined) was somewhat further in advance than was intended when they first came in contact with the enemy. The route lay towards the south-south-east, across a sloping plateau intersected by dry watercourses, towards a deep ravine, full of boulders and huge detached rocks.[100] The morning was bright and clear, with a brilliant sun, but there was no wind, as at El-Teb, to carry off the smoke. This, as will be seen, became important. [Illustration: BATTLE OF TAMAAI.] As the brigades advanced the black forms of the Soudanese were seen ranged along the hills on the front and right of the British force. Two squadrons of cavalry, together with some Abyssinian scouts, were sent forward to skirmish and endeavour to clear the bushes through which the infantry had to advance. The skirmishers had not gone far before they became hotly engaged. Captain Humphreys, in command, sent back word that the ravine was occupied in force. Although this was only a few hundred yards in front, it was so hidden by bushes as to be invisible to the infantry. About twenty minutes after starting, the 2nd Brigade was halted to re-form itself from the somewhat loose order into which it had fallen in its advance over the rough ground. At half-past eight it was moving slowly towards the ravine, which extended itself irregularly all along the front, and was from 900 to 1,000 yards off. The 1st Brigade, 700 yards distant to the right and rear, was timing its movements and taking its ground step by step with the 2nd Brigade.