should be sent back to Manaus. 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 honor 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.