As wind is known to be composed of two distinct gases, Crusoe felt perfectly safe in replying "Yes" with his tail. Immediately after he added, "Hallo! did you hear that?" with his ears. Dick did hear it, and sprang hastily to his feet, as a sound like, yet unlike, distant thunder came faintly down upon the breeze. In a few seconds the sound increased to a roar in which was mingled the wild cries of men. Neither Dick nor Crusoe moved, for the sounds came from behind the heights in front of them, and they felt that the only way to solve the question, "What can the sounds be?" was to wait till the sounds should solve it themselves. Suddenly the muffled sounds gave place to the distinct bellowing of cattle, the clatter of innumerable hoofs, and the yells of savage men, while at the same moment the edges of the opposite cliffs became alive with Indians and buffaloes rushing about in frantic haste--the former almost mad with savage excitement, the latter with blind rage and terror. On reaching the edge of the dizzy precipice, the buffaloes turned abruptly and tossed their ponderous heads as they coursed along the edge. Yet a few of them, unable to check their headlong course, fell over, and were dashed to pieces on the rocks below. Such falls, Dick observed, were hailed with shouts of delight by the Indians, whose sole object evidently was to enjoy the sport of driving the terrified animals over the precipice. The wily savages had chosen their ground well for this purpose. The cliff immediately opposite to Dick Varley was a huge projection from the precipice that hemmed in the gorge, a species of cape or promontory several hundred yards wide at the base, and narrowing abruptly to a point. The sides of this wedge-shaped projection were quite perpendicular--indeed, in some places the top overhung the base--and they were at least three hundred feet high. Broken and jagged rocks, of that peculiarly chaotic character which probably suggested the name to this part of the great American chain, projected from and were scattered all round the cliffs. Over these the Indians, whose numbers increased every moment, strove to drive the luckless herd of buffaloes that had chanced to fall in their way. The task was easy. The unsuspecting animals, of which there were hundreds, rushed in a dense mass upon the cape referred to. On they came with irresistible impetuosity, bellowing furiously, while their hoofs thundered on the turf with the muffled continuous roar of a distant but mighty cataract; the Indians, meanwhile, urging them on by hideous yells and frantic gestures.