Nick got up, rubbing the green mud from his elbows and knees, and staring in wonder at the object the fall of which had so astonished him. An examination of it did not tend to remove his perplexity. It was a large heavy piece of wood, shaped evidently by the axe, so as to resemble a rude arrow, but as thick as the mast of a large cutter. To the end of this was attached an iron head of a corresponding size. It had penetrated deep into the ground, and would have been sufficient to shatter Nick's skull like an icicle if it had come in contact with it. "Whatever can that be?" he exclaimed; "and how came it up there?" "A hippopotamus trap," said the missionary; "and it is a good job that it has not proved a man trap too. You must not leave your companions in this wild country, Nick, or even your good luck won't keep you out of trouble. I noticed the trap as we passed, and then perceived a minute or two afterwards that you were not with us. It is fortunate I turned back and called you. If you hadn't been running fast it might have caught your head, or at all events your leg." By this time they were rejoined by the rest of the party, and De Walden proceeded to explain to the boys the curious construction of the machine from which Nick had had so narrow an escape. It was common enough, he told them, in the neighbourhood of the haunts of the hippopotamus. The stem of a young tree, a foot or so in diameter, was cut off at the length of about four feet. A strong and sharp iron head was fixed at one end, and at the other an eye, to which a string was attached. This rude shaft was then hung up to the branch of a large tree immediately over the path by which the hippopotamuses were wont to go down to the river. The string was passed over the branch, round a projecting root at the bottom of the tree, and straight across the path, being ultimately secured to a peg driven into the earth. This string came into contact with the feet of the hippopotamus, which, in walking, shambles along, scarcely raising its legs from the ground. The string being in this manner broken, the heavy beam instantly falls, usually striking the hippopotamus in the back, and penetrating the vitals. The blow is almost always mortal. Even if the animal is not killed on the spot, it is so badly wounded that it dies shortly afterwards. Sometimes, to make assurance doubly sure, Mr De Walden told them, the iron is steeped in poison. "There didn't need that," said Nick, as he contemplated the barbed point, as big as the fluke of an anchor, and sharp as an arrow. "The iron head would have finished me off very handsomely, without troubling the poison-makers. Well, I'll take care another time, as the children say, and I can't do more. Let's be off now. I want to get to our quarters for the night." CHAPTER TWENTY ONE. THE BASUTO KRAAL--QUEEN LAURA--THE QUEEN'S NARRATIVE--THE WRECK OF THE GROSVENOR--SUFFERINGS OF THE SURVIVORS--THE BASUTO CHIEF--DE WALDEN'S JOY.