“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.

“Of course,” answered Lady Olivia, detaching from her belt the little leather bag in which she usually carried her handkerchief, scent-bottle, and other odds and ends. “I think that several of them are quite good; but my husband declares that they are not worth the trouble of picking up.”

“And he is quite right, so far as this one, at least, is concerned,” remarked the professor, as he drew forth a stone and held it up to the light for a moment. “This also,” as he drew forth a second, looked at it, and threw it away. “Ah!” he exclaimed, as he produced a third, “this looks more promising.”

He examined the stone very carefully—it was about the size of a plover’s egg—and presently said, as he handed it back—

“My dear lady, permit me to congratulate you. You have been fortunate enough to secure an exceptionally magnificent stone, without doubt. It is, of course, somewhat difficult to judge of the precise value of a gem in its rough, uncut state, but I should say that you have there a stone that will prove almost unique, not only as to size, but also for its perfect colour. Have you any more like it?”