“It is most beautiful and wonderful,”—­answered Catherine, in her coldest tone of conventional politeness, “And so unusual!”

His eyebrows went up with a slightly quizzical.

“Yes, I suppose it is unusual,” he said—­“I am always forgetting that what is not quite common seems strange!  But really the arrangement is very simple.  The yacht is called the ’Dream’—­and she is, as her name implies, a ‘dream’ fulfilled.  Her sails are her only motive power.  They are charged with electricity, and that is why they shine at night in a way that must seem to outsiders like a special illumination.  If you will honour me with a visit to-morrow I will show you how it is managed.”

Here Captain Derrick, who had been standing close by, was unable to resist the impulse of his curiosity.

“Excuse me, sir,”—­he said, suddenly—­“but may I ask how it is you sail without wind?”

“Certainly!—­you may ask and be answered!” Santoris replied.  “As I have just said, our sails are our only motive power, but we do not need the wind to fill them.  By a very simple scientific method, or rather let me say by a scientific application of natural means, we generate a form of electric force from the air and water as we move.  This force fills the sails and propels the vessel with amazing swiftness wherever she is steered.  Neither calm nor storm affects her progress.  When there is a good gale blowing our way, we naturally lessen the draft on our own supplies—­but we can make excellent speed even in the teeth of a contrary wind.  We escape all the inconveniences of steam and smoke and dirt and noise,—­and I daresay in about a couple of hundred years or so my method of sailing the seas will be applied to all ships large and small, with much wonder that it was not thought of long ago.”

“Why not apply it yourself?” asked Dr. Brayle, now joining in the conversation for the first time and putting the question with an air of incredulous amusement—­“With such a marvellous discovery—­if it is yours—­you should make your fortune!”

Santoris glanced him over with polite tolerance.

“It is possible I do not need to make it,”—­he answered, then turning again to Captain Derrick he said, kindly, “I hope the matter seems clearer to you?  We sail without wind, it is true, but not without the power that creates wind.”

The captain shook his head perplexedly.

“Well, sir, I can’t quite take it in,”—­he confessed—­“I’d like to know more.”

“So you shall!  Harland, will you all come over to the yacht to-morrow?  There may be some excursion we could do together—­and you might remain and dine with me afterwards.”

Mr. Harland’s face was a study.  Doubt and fear struggled for the mastery in his expression and he did not at once answer.  Then he seemed to conquer his hesitation and to recover himself.

“Give me a moment with you alone,”—­he said, with a gesture of invitation towards the deck saloon.