As afternoon drew on, Ned and his chums began to husband their strength. They dug the pickaxe and spades more lightly into the baked clay, and played themselves at working as much as possible. At last the sun dropped to the horizon, and they were driven back to the tronk. As they approached, our heroes looked at the walls and building with keen speculation. The front was the portion occupied by the warders. A couple of men were supposed to watch the back from opposite corners, but, as Ned shrewdly surmised, they did not keep a very strict sentry, otherwise his friends could not have got over the wall as they had done the night before. For the few moments that twilight remained in the cell, they examined the ground and gave their Kaffir friends directions. The poor fellows listened attentively to their chosen leader, Cocoeni, and showed that they were ready. Then darkness came, and they began without delay. To prevent the sounds being heard, Ned and his chums began to sing; the others also made as much gabble as they could. In the other cells, which were divided by the iron sheeting, they could hear the prisoners quite distinctly. It was to prevent them hearing the pickaxe at work that they were making the row, but as for the Boers, they had no fear of them troubling to stop a wrangle or a ditty as long as it was not patriotic. Ned took care of this by starting and keeping up a few of Sankey's hymns which he knew. While they were singing they likewise prayed fervently for their deliverance. Cocoeni took the pickaxe, as he was the strongest man there. With a few deft strokes he had broken the hardened surface of the floor; then, while he dug, the others scooped the earth out of the hole with their hands. He went down by the side of the wall until he had cleared the foundations; after this he began to tunnel. It took them till long after midnight before they got to the outside of the wall; then they began to dig upwards. They worked very carefully at this portion, and carried the debris into the cell by relays. At last they had reached the surface, and as some of the earth fell in upon them, they were able to see the stars. To their joy this side of the wall was buried in darkness, for the moon was on the other side. Ned looked out carefully as soon as the passage was wide enough. Halfway across the yard the shadow fell, leaving a patch of whiteness for some fifteen feet between that and the outer wall, which was about ten feet in height. At each angle a sentry-box stood clearly revealed. As far as Ned could see, they were unoccupied. The sentinels had evidently left their post, and the passage was clear. One by one they crept out, Cocoeni bringing the pickaxe with him. As they stood by the wall, Cocoeni whispered softly to Ned-- "Wait, Baas. I creep round and see if no one about." He crept off without a sound, while they watched and listened. In a moment more he was back.