One thing which his couriers at last began to report to him was a cause of surprise. They said that the level of the water was rapidly falling. Some who had gone far toward the east declared that it had gone down hundreds of feet. But the professor reflected that this was impossible, because evaporation could not account for it, and he could not persuade himself that so much water could have found its way into the interior of the crust. He concluded that his informants had allowed their hopes to affect their eyesight, and, strong as usual in his professional dogmas, he made no personal examination. Besides, Professor Pludder was beginning to be shaken in his first belief that all trouble from the nebula was at an end. Once having been forced to accept the hypothesis that a watery nebula had met the earth, he began to reflect that they might not be through with it. In any event, he deemed it wise to prepare for it if it _should_ come back. Accordingly he advised that the population that remained should concentrate in the stronger houses, built of stone, and that every effort should be made to strengthen them further and to make the roofs as solid as possible. He also directed that no houses should be occupied that were not situated on high ground, surrounded with slopes that would give ready flow to the water in case the deluging rain should recommence. He had no fixed conviction that it would recommence, but he was uneasy, owing to his reflections, and wished to be on the safe side. He sent similar instructions as far as his horsemen could reach. The wisdom of his doubts became manifest about two weeks after the arrival of the President's party. Without warning the sky, which had been perfectly blue and cloudless for a month, turned a sickly yellow. Then mists hid the head, and in a little while the entire outline of Pike's Peak, and after that a heavy rain began. Terror instantly seized the people, and at first nobody ventured out of doors. But as time went on and the rain did not assume the proportions of the former _débâcle_, although it was very heavy and continuous, hope revived. Everybody was on the watch for a sudden clearing up. Instead of clearing, however, the rain became very irregular, gushing at times in torrents which were even worse than the original downpour, but these tremendous gushes were of brief duration, so that the water had an opportunity to run off the higher ground before the next downpour occurred. This went on for a week, and then the people were terrified at finding that water was pouring up through all the depressions of the land, cutting off the highlands from Pike's Peak with an arm of the sea. It was evident that the flood had been rapidly rising, and if it should rise but little higher they would be caught in a trap. The inland sea, it was clear, had now invaded the whole of Colorado to the feet of the mountains, and was creeping up on them.