The Egyptian cavalry had meanwhile a somewhat different view of the spectacle. Working on the right of the 21st Lancers, and keeping further from the river, the leading squadrons had reached the extreme western end of the Kerreri ridge at about seven o'clock. From here the Mahdi's Tomb was visible, and, since the rocks of Surgham did not obstruct the view from this point, the British officers, looking through their field-glasses, saw what appeared to be a long column of brown spots moving south-westwards across the wide plain which stretches away to the west of Omdurman. The telescope, an invaluable aid to reconnaissance, developed the picture. The brown objects proved to be troops of horses grazing; and beyond, to the southward, camels and white flapping tents could be distinguished. There were no signs that a retreat was in progress; but from such a distance--nearly four miles--no certain information could be obtained, and Colonel Broadwood decided to advance closer. He accordingly led his whole command south-westward towards a round-topped hill which rose about four miles from the end of the Kerreri ridge and was one of the more distant hill features bounding the plain on the western side. The Egyptian cavalry moved slowly across the desert to this new point of observation. On their way they traversed the end of the Khor Shambat, a long depression which is the natural drainage channel of the plains of Kerreri and Omdurman, and joins the Nile about four miles from the city. The heavy rain of the previous night had made the low ground swampy, and pools of water stood in the soft, wet sand. The passage, however, presented no great difficulty, and at half-past eleven the Egyptian squadrons began to climb the lower slopes of the round-topped hill. Here the whole scene burst suddenly upon them. Scarcely three miles away the Dervish army was advancing with the regularity of parade. The south wind carried the martial sound of horns and drums and--far more menacing--the deep murmur of a multitude to the astonished officers. Like the 21st Lancers--three miles away to their left, at the end of the long sandy ridge which runs westward from Surgham--the soldiers remained for a space spell-bound. But all eyes were soon drawn from the thrilling spectacle of the Dervish advance by the sound of guns on the river.