were mere shadows upon the distant skyline. On the fourth day after leaving Manaos we turned into a tributary which at its mouth was little smaller than the main stream. It narrowed rapidly, however, and after two more days' steaming we reached an Indian village, where the Professor insisted that we should land, and that the Esmeralda should be sent back to Manaos. We should soon come upon rapids, he explained, which would make its further use impossible. He added privately that we were now approaching the door of the unknown country, and that the fewer whom we took into our confidence the better it would be. To this end also he made each of us give our word of honour that we would publish or say nothing which would give any exact clue as to the whereabouts of our travels, while the servants were all solemnly sworn to the same effect. It is for this reason that I am compelled to be vague in my narrative, and I would warn my readers that in any map or diagram which I may give the relation of places to each other may be correct, but the points of the compass are carefully confused, so that in no way can it be taken as an actual guide to the country. Professor Challenger's reasons for secrecy may be valid or not, but we had no choice but to adopt them, for he was prepared to abandon the whole expedition rather than modify the conditions upon which he would guide us.
It was August 2nd when we snapped our last link with the outer world by bidding farewell to the
