“For the next sixteen miles the course of the river is unimpeded by any serious obstacle, still for every yard the current runs as strong as the Thames in flood, on every side the basalt mountains radiate their heat, and everywhere the sunken rocks lie in wait for the unwary steersman. At the end of this distance the cataract of Ambako is reached, a very different piece of water to that of Semneh. At the latter spot an obstacle to navigation was formed by the volume of the Nile being pent into a narrow gorge; at Ambako the same effect is produced by a broad expanse of river being choked by an innumerable mass of reefs and islets. At full high Nile, when the lower rocks are buried deep beneath the surface, the cataract is not a formidable one; but as the river falls and reef after reef makes its appearance, the difficulties of navigation increase, until at low Nile the cataract has become impassable for the larger native craft, and is a grave source of difficulty even to the buoyant English whalers. “Here every means of propulsion has to be employed. At one moment the whalers, under the lee of some islet, may be paddled gently up a narrow lane of almost stagnant water. Then, as the shelter of the rock is lost, though its crew pull for dear life, it is carried back some hundreds of yards until a point of vantage is reached near the shore. Next the track line is got out, and step by step the boat is hauled round a projecting point by a treble boat’s crew. Now a fresh breeze and a clear reach of moderate water make it just possible to gain a few hundred yards by making the very most of sails and oars; then a bit of shelving shore is met with, along which good progress may be made by half the crew tracking, while the remainder stay on board and use their punt-poles. At length, by dint of perseverance, the five miles of rapid are surmounted in twice as many hours of incessant labour, and another eight miles of open water are entered on.”[257] Though no two cataracts are exactly alike, their general features are much the same, and therefore it is enough merely to mention the others passed by the XVIIIth. Above the rapids of Ambako came the cataract of Tanjur, which, though only two miles and a half long, usually took the boats a whole day to ascend, and fifteen miles higher up was another rapid, nearly as troublesome as that of Semneh. This was succeeded by ten miles of smooth water running between hills crowned with ruins, relics of a nation so ancient that its very name has been forgotten. Then followed the cataract of Dal, round which stores had to be carried for three or four miles by hand; these rapids once passed, the boats entered a long reach of calm but swift-running water 100 miles in length, at the head of which two more cataracts, those of Kaiber[258] and Hannek, had to be surmounted. From Hannek to Korti the navigation of the Nile was fairly easy.