"I don't know," answered the professor. "'Msusa speaks fairly enough, but one can never tell. Treachery, so far from being a crime, almost amounts to a virtue, under certain circumstances, with all these African savages; and I must confess that I have noticed one or two little things that, to me, seemed to bear rather a sinister significance. But what can we do? We cannot take 'Msusa by the scruff of the neck and insist upon his becoming our guide to the river." "Can we not?" cut in Lethbridge, dryly. "I am by no means so sure of that. But an idea has just occurred to me. Mildmay will have been on the look-out for some sign of us, at least from breakfast-time to-day, and, if I know anything of him, he is still looking out, and will continue to do so until darkness sets in--perhaps even later. Now, my idea is this--and I am sorry that it did not occur to me earlier in the day. Here are we, four lost men, in a fine open space, with ample room to light four fires at a considerable distance apart. The evening is fine; there is no wind; and the smoke from those fires would rise to a considerable height into the air. Now, if Mildmay should happen to notice four distinct columns of smoke rising above the tree-tops--" "Of course," interrupted von Schalckenberg, "he would at once connect them with us, and would come in the _Flying Fish_ to investigate. It shall be done at once." And, turning away, he forthwith entered into energetic conversation with 'Msusa, which ultimately resulted in that savage giving certain instructions to his friends, who, after a tremendous amount of palaver, interspersed with frequent references from 'Msusa to the professor, at length set to work to gather four large piles of branches, dry leaves, and other combustibles, which they proceeded to arrange on spots indicated by von Schalckenberg. As soon as the piles were of sufficient size to yield a good dense body of smoke they were simultaneously ignited by the four white men--by the simple agency of an ordinary match, to the intense astonishment and admiration of the blacks--and then the quartette sat down patiently to await events, while 'Msusa and his friends, incited thereto by the professor, continued to pile upon the fires further quantities of grass, green branches, and other things calculated to produce the maximum quantity of smoke. The result was that in a few minutes four distinct columns of brownish-grey smoke were going up straight into the sky, some hundreds of feet above the tops of the highest trees, and finally spreading out and mingling into one great cloud that would be distinctly visible, in that atmosphere, anywhere within a distance of twenty miles. Lethbridge leaned back on his elbow and contemplated the four tall smoke columns with an expression of very considerable satisfaction.