"It has just occurred to me that the present is an excellent opportunity for us to test our wireless telephones by calling up our friends on the beach."

And, entering the pilot-house, he went up to the instrument that was there fixed, and, opening it, laid his finger on one of two small k.n.o.bs that it contained. The little bell that formed part of the instrument at once started ringing--as did a similar bell in every room of the ship--and so continued for about half a minute, when it ceased for about two seconds, and then went on again.

"Good!" remarked the professor, removing his finger from the b.u.t.ton, and so stopping the ringing of the bell, as he drew out a small tube and inserted it's end in one ear; "some one among our friends hears us."

Then he advanced his mouth to the mouthpiece, and spoke into it--

"Hillo! who are you?"

"I am Elphinstone," came the instant and clear reply. "Is that the _Flying Fish_?"

"Yes," answered von Schalckenberg. "We are now at the village, and we thought it an excellent opportunity to test the telephones. They appear to answer perfectly; for I can hear you as distinctly as though you were at my elbow. Can you hear me fairly well?"

"Splendidly; quite as well as you can hear me, I should say," replied Sir Reginald. "I congratulate you, Professor, upon the success of your latest invention. It is a most useful instrument; and I can easily imagine a number of circ.u.mstances under which it might prove of the utmost value to us. An idea has just occurred to me. How would it do, while we are about it, to ascertain the greatest distance at which it is possible to communicate intelligibly with each other?"

"Excellent!" answered von Schalckenberg. "We will shut ourselves in, ascend to a height of ten thousand feet, into the calm belt, and then proceed at full speed directly away from you. Keep your finger on the black b.u.t.ton of your instrument, please, for our guidance; and when our bell ceases to sound we shall know that we have lost touch with you."

"Right!" came the answer. And instantly all the bells in the ship again started ringing.

At the same moment the professor closed the door and windows of the pilot-house, and injected a strong jet of vapour into the air-chambers, causing the ship to rise rapidly into the air. Then he sent the engines full speed ahead, and pointed the ship's sharp snout on a compa.s.s bearing that left the party on the beach directly astern of her.

For three-quarters of an hour the bells in the ship continued to ring, at first strongly, and then gradually with diminishing strength; and finally, when the ship had been running continuously at full speed for fifty minutes, they became inaudible.

The professor's face, meanwhile, was a picture of ever-growing delight.

"If we can continue to hear the bell for a quarter of an hour I shall be quite satisfied," he had remarked to Mildmay, as the ship first rose into the air; "for by that time we shall be quite fifty miles distant from the beach."

And when the quarter of an hour had elapsed with no perceptible diminution in the volume of sound, his growing satisfaction had been faithfully mirrored by the steadily expanding smile upon his expressive features. Finally, when at length the bells ceased to ring, he exclaimed--

"Well! who would have believed it? Here have I, a poor silly scientist, been hoping that my little invention would prove effective for as long a distance as fifty miles; and behold, at the distance of one hundred and twenty miles from our friends we have only just lost touch with them.

Let us try back, my friend; turn the ship round, and we will then note how far we have to run before we can speak clearly to each other."

Mildmay accordingly put the helm hard over, and when the compa.s.s 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 k.n.o.b 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.

"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?"

Further investigation proved that Lady Olivia had another that was almost, if not quite, the equal of the first, as well as three others of somewhat smaller size, but equal beauty of colour; and when, presently, the professor proceeded to examine Sir Reginald's find, it became at once apparent that the rubies to be found in this particular locality were likely to prove exceptionally valuable from their extreme richness of colour.

"And these," exclaimed von Schalckenberg, enthusiastically, "are the results of but a few hours' search! Surely there must be a ruby mine of almost fabulous richness somewhere close at hand. Now is the time for me to acquire a little of that wealth of which I am in such urgent need."

And, raising his hat to Lady Olivia, he turned away. But it was presently noticed that, instead of examining the pebbles on the beach, as the rest were doing, he went straight to the foot of the low cliff at the upper edge of the beach, scrutinising its face very closely, and foot by foot, as he pa.s.sed slowly along it. When last particularly noticed, he was seen to be apparently digging into the soil of the cliff-face, here and there, with his pocket-knife.

At length the sound of a gong beaten on board the _Flying Fish_ gave notice that afternoon tea was ready for whosoever chose to partake of that refreshment; and the two ladies and little Ida--all three of whom held the inst.i.tution in great respect--at once gladly turned their steps toward the ship, for they were fatigued and hot with their unwonted exertions, and felt that a cup of tea was precisely what they needed for their restoration. The men of the party, also, had by this time drifted almost insensibly into the habit of joining the ladies at this function; thus it came to pa.s.s that within the half-hour the entire party had gathered beneath the awnings, and, ensconced in comfortable basket chairs, were leisurely sipping the fragrant cup that is said to cheer and certainly does not inebriate, while they discussed in desultory fashion their afternoon's experiences, and compared their finds. All, that is to say, with the exception of von Schalckenberg, who, in his usual absent-minded way, was to be seen, about a mile distant, still prodding and poking at the cliff-face as industriously and with as deep an absorption as though so important a function as afternoon tea was quite unknown to him.

"Let us call the beggar up with one of his own telephones," said Lethbridge, in response to some remark of Lady Olivia's anent the professor's absorption. "If we don't he will stay there until darkness falls, and then wonder how the d.i.c.kens he got there. Here, Ida, come you and call up the professor, sweetheart; he will perhaps listen to you, though it is very doubtful whether he would to me." And, drawing his telephone from his pocket, he pressed the b.u.t.ton, while Ida--with whom the ex-colonel was a great favourite--came and stood obediently by his side. As usual, everybody else's telephone, as well as all the bells in the ship, at once started ringing.

"Now," continued Lethbridge, gravely, "that is the fault that I have to find with these otherwise wonderfully clever contrivances of von Schalckenberg's. You want to communicate with a certain person by means of your own instrument, and you at once attract the attention of everybody else who happens to possess one. I must remember to ask the worthy man if he cannot remedy that defect. Ah, there he is," as the bells ceased for a moment to tinkle. "Now then, Ida, put this in your ear, and then tell the professor, through that mouthpiece, that afternoon tea is on."

The child at once did so, calling into the receiver--

"Professor, Professor, can you hear me?"

"Oh yes, of course I can," replied the professor's voice. "What is the matter, my dear?"

"Tea is ready!" proclaimed Ida, shortly.

"Is that so?" answered the professor. "All right, little one; I should like a cup of tea very much, for I am terribly thirsty. But I cannot come just now, for I am very busy. So you take your tea yourself, and enjoy it, eh?"

"What are you so dreadfully busy about, Professor?" demanded the child.

"I am busy at the making of my fortune," answered the professor. "You can tell your papa that I believe I have found the heart of the ruby mine; and, if so, there will be rubies enough for us all and to spare.

I will tell you more about it when I turn up for dinner."

The professor duly turned up, very hot and tired--not to say dirty--as the first star made its appearance in the eastern sky; and the result of his afternoon's labour was represented by some forty rubies of a size, and fire, and richness of colour that threw those found by the rest of the party entirely in the shade.

His story was very simple. He explained that the fact of rubies being found upon the beach had led him to the conviction that they must originally have come from the soil of the cliff-face; and he had accordingly devoted himself to the task of examining the bare soil at those spots where it had crumbled away. The result, he said, was that he had ultimately come upon a place where, upon careful inspection, he had found no fewer than three rubies just showing through the soil, within a foot of each other. These he had, of course, straightway dug out; and in the act of doing so had disclosed others, the ultimate result being the unearthing of the superb stones that he had brought back with him. His opinion, he explained, was that, judging from the indications already seen, there would be found to be a very considerable "pocket" of rubies at no great distance in from the cliff-face; and that the best plan would be for the five men to work conjointly, with picks and shovels, finally dividing the proceeds between the members of the party. As for the ladies, if they chose to amuse themselves by searching the beach, the professor was of opinion that they might meet with sufficient success to render it fully worth their while.

On the following morning, accordingly, the _Flying Fish_ was moved close up to the scene of the professor's discovery, and the men, suitably attired and provided with picks, shovels, and bars, went to work upon the top edge of the cliff, breaking down and shovelling away the soil as directed by the professor; but up to lunch time their efforts had been rewarded by the finding of but one ruby. This, however, von Schalckenberg explained, was not to be wondered at, as it would probably take them two or three days to get down to the spot at which he expected to find the "pocket." This same "pocket," he further explained, might possibly have been much more quickly reached, and with much less labour, by digging into the face of the cliff, instead of downward. This, however, he a.s.serted, would have exposed them all to the very great risk of an almost certain fall of earth; he had therefore deemed it wise to adopt the safer method, even though it involved the expenditure of a very considerably greater amount of labour.