The caravan proceeded on its way, men and animals labouring to the utmost; when, at a point where the sides of rock seemed nearly to close above them, a narrow line of sky only being visible, a great rock came crushing and leaping down, bounding from side to side with a tremendous uproar, and bringing down with it a shower of smaller rocks, which it had dislodged in its course. The bottom of the ravine was here about twelve yards wide, and happened to be unusually level. The great rock, which must have weighed half a ton, fell on one side of the leading waggon and burst into fragments which flew in all directions. Fortunately no one was hurt, but a scream of dismay broke from the natives. "Steady!" Mr Harvey shouted; "push on ahead; but each man keep to his work--the first who attempts to run and desert the waggons I will shoot through the head." "Tom, go on a hundred yards in front, and keep that distance ahead of the leading waggon. Shoot down at once any one who attempts to pass you." Rock followed rock in quick succession; there was, however, fortunately a bulge in the cliff on the righthand side, projecting some twenty feet out, and as the blocks struck this they were hurled off to the left side of the path. Seeing this Mr Harvey kept the waggons close along on the right, and although several of the oxen and three or four of the men were struck by detached fragments from above, or by splinters from the stones as they fell, none were seriously injured. Long after the caravan had passed the point the rocks continued to thunder down, showing Mr Harvey that those above were unable to see to the bottom of the gorge, but that they were discharging their missiles at random. A short distance farther a cross ravine, a mere cleft in the rock, some five feet wide at the bottom, was passed, and Mr Harvey congratulated himself at the certainty that this would bar the progress of their foes above, and prevent the attack being renewed from any point farther on. At this point so formidable an obstacle was met with in a massive rock, some thirty feet high, jammed in the narrowest part of the ravine, that the waggons had to be emptied and hauled by ropes up the almost perpendicular rock, the oxen being taken through a passage, which with immense labour the men managed to clear of stones, under one of the angles of the rock. It was not until after dark that they reached the spot where the ravine again widened out into a valley, having spent sixteen hours in accomplishing a distance of only three miles. However, all congratulated themselves that two-thirds of their labour was over, and that but one more defile had to be surmounted. The rear-guard remained encamped at the opening of the defile, but the night passed without interruption, the natives being doubtless disheartened by the failure to destroy the caravan by rocks from above.