Mildmay accordingly put the helm hard over, and when the compass showed that the ship was once more pointing directly toward the spot on the beach where the remainder of the party had been left, the professor drew out his watch, and carefully noted the time. Almost immediately the bells again began to tinkle, at first very faintly and intermittently, but rapidly increasing in strength as the ship sped back over the ground that she had traversed a few minutes earlier. By the time that she had run ten miles on her return journey the bells were again ringing quite strongly. "Stop her!" commanded von Schalckenberg. "We are now one hundred and ten miles from our friends, and I think we ought to be within speaking distance of them. Let us try." He touched the red knob of the instrument, and at the same time inserted the end of the tube in his ear. Almost instantly a faint but quite distinct shout came to him: "Hillo, von Schalckenberg, where are you now?" he heard Sir Reginald's voice inquire. "We are just one hundred and ten miles distant from you," answered the professor. "Can you hear me distinctly?" "Yes, quite distinctly; although your voice does not sound quite so loud as it did," came the reply. "It sounds as though you were about a hundred feet away." "Still, if you can hear me clearly enough to distinguish what I say, it is good enough. You will hear me more distinctly as we shorten the distance between you and ourselves. By the way, have you met with any luck yet in your search for rubies?" "Yes," answered Sir Reginald. "During these experiments of yours I have been lying down on the beach, turning over the pebbles within reach, and have found two rather fine stones that look like rubies. You will be able to say whether they are or no when you see them." "Which will be within the hour," answered the professor; "for we are now about to return to you at full speed. Many thanks, my friend, for giving so much time to my experiment. I need not now trouble you any further; so get to work in earnest, and see how many more rubies you can find by the time that we arrive." It was exactly fifty-five minutes later that the _Flying Fish_, still at a height of ten thousand feet above the sea-level, arrived over the beach where the rest of the party were seen wandering slowly hither and thither, and gently settled down in their midst. "Well, my friends, what luck, so far?" demanded the professor, as he and Mildmay emerged from the ship's diving-chamber, and joined Sir Reginald and Lady Olivia on the beach. "That is for you to say," answered Sir Reginald, with a laugh. "I have found another likely looking stone since I last spoke to you; and Lady Olivia, here, has a whole pocketful, but most of them, I am afraid, are rather more than doubtful." "May I be permitted to see them?" asked von Schalckenberg, holding out his hand, with a smile.