They showed us also an enormous hanging stone perched on the edge of a volcano’s crater—the highest summit in the whole island. Although it was very far below us, we could see it quite plainly; and it looked wobbly enough to be pushed off its perch with the hand. There was a legend among the people, they said, that when the greatest of all Popsipetel kings should be crowned in the ivory chair, this hanging stone would tumble into the volcano’s mouth and go straight down to the centre of the earth. [Illustration: “The Whispering Rocks”] The Doctor said he would like to go and examine it closer. And when we were come to the lip of the volcano (it took us half a day to get up to it) we found the stone was unbelievably large—big as a cathedral. Underneath it we could look right down into a black hole which seemed to have no bottom. The Doctor explained to us that volcanoes sometimes spurted up fire from these holes in their tops; but that those on floating islands were always cold and dead. “Stubbins,” he said, looking up at the great stone towering above us, “do you know what would most likely happen if that boulder should fall in?” “No,” said I, “what?” “You remember the air-chamber which the porpoises told us lies under the centre of the island?” “Yes.” “Well, this stone is heavy enough, if it fell into the volcano, to break through into that air-chamber from above. And once it did, the air would escape and the floating island would float no more. It would sink.” “But then everybody on it would be drowned, wouldn’t they?” said Bumpo. “Oh no, not necessarily. That would depend on the depth of the sea where the sinking took place. The island might touch bottom when it had only gone down, say, a hundred feet. But there would be lots of it still sticking up above the water then, wouldn’t there?” “Yes,” said Bumpo, “I suppose there would. Well, let us hope that the ponderous fragment does _not_ lose its equilibriosity, for I don’t believe it would stop at the centre of the earth—more likely it would fall right through the world and come out the other side.” Many other wonders there were which these men showed us in the central regions of their island. But I have not time or space to tell you of them now. Descending towards the shore again, we noticed that we were still being watched, even here among the highlands, by the Bag-jagderags who had followed us. And when we put to sea once more a boatload of them proceeded to go ahead of us in the direction of Popsipetel. Having lighter canoes, they traveled faster than our party; and we judged that they should reach the village—if that was where they were going—many hours before we could. The Doctor was now becoming anxious to see how Long Arrow was getting on, so we all took turns at the paddles and went on traveling by moonlight through the whole night. We reached Popsipetel just as the dawn was breaking.