"I understand, baas," he said, and at once turned and went off. The others hurried to their respective posts, and then turned round and gazed at the spot where the light would be shown. In their anxiety and excitement the time seemed interminable, and each began to think that the native had somehow blundered; at last the light appeared, and they turned at once to their work. Half a minute sufficed to light the fuses, and then they hurried away cautiously until past all the waggons, and then at full speed along the hillside, their thickly-padded shoes making no noise upon the rocks. Knowing that they were sure to be confused as to the time, they had calculated before the sun had set how far they could run in three minutes, which should be, if all went well, the time they would have after leaving the yard. They thought that even on the rough ground, and in the dark, they could make a hundred and fifty yards a minute, and at about four hundred and fifty from the waggons there was a low ridge of rock behind which they would obtain protection from all fragments blown directly outwards. Chris was the first to arrive, for the trucks with the cannon were those farthest away from the bridge, and he was able to run for some distance along the line before making for the elope, and therefore travelled faster than his companions, who had farther to run on broken ground. In half a minute they rushed up almost together. "Throw yourselves down," Chris shouted; "we shall have it directly." Twenty seconds later there was a tremendous roar and a blinding crash, and they felt the ground shake. Almost simultaneously came eight others, then in quick succession followed six other reports, and mingled with these a confused roar of innumerable shots blended together. There was a momentary pause, and then a deafening clatter as rifles, fragments of iron and wood came falling down over a wide area. Several fell close to where the lads were crouched against the rock, but none touched them. For a full half-minute the fragments continued to fall, then the boys stood up and looked round. It was too dark to see more than that the yard was a chaos; the long lines of waggons, the huts and buildings, had all disappeared; loud shouts could be heard from the other side of the bridge, but nearer to them everything was silent. There was no doubt that the success of the attempt was complete, and the lads walked back quietly until they were at the spot where the horses had been placed, Jack overtaking them just as they reached it. "It was terrible, baas," he said in an awed voice. "Jack thought his life was gone. Things fell on the rock but could not break it." "Nothing short of one of those big cannon would have done that, Jack. Well, we shall see in the morning what damage is done."