“Frenchman, it is the tricolor that flies on yonder ship!  Frenchman, it is a very part of France that is approaching you!  Frenchman, would you be so criminal as to strike it?”

But my intervention will not be necessary.  Thomas Roch is not a prey to one of the fits to which he was formerly subject.  He is perfectly sane.

When he found himself facing the flag he understood—­and drew back.

A few pirates approach to lead him to the trestle again.  He struggles and pushes them from him.

Ker Karraje and Engineer Serko run up.  They point to the rapidly advancing ship.  They order him to launch his engines.

Thomas Roch refuses.

Captain Spade and the others, mad with rage, menace him—­curse him—­strike him—­try to wrest the phial from him.

Roch throws it on the ground and crushes it under foot.

Then panic seizes upon the crowd of wretches.  The cruiser has passed the zone and they cannot return her fire.  Shells begin to rain all over the island, bursting the rocks in every direction.

But where is Thomas Roch?  Has he been killed by one of the projectiles?  No, I see him for the last time as he dashes into the passage.

Ker Karraje, Engineer Serko and the others follow him to seek shelter inside of Back Cup.

I will not return to the cavern at any price, even if I get killed by staying where I am.

I will jot down my final notes and when the French sailors land on the point I will go—­

END OF ENGINEER SIMON HART’S NOTES.

CHAPTER XVIII.

ON BOARD THE “TONNANT.”

After the failure of Lieutenant Davon’s mission with the Sword, the English authorities waited in vain for the expedition to return, and the conviction at length gained ground that the bold sailors had perished; but whether the Sword had been lost by striking against a rock or had been destroyed by Ker Karraje’s pirates, could not, of course, be ascertained.

The object of the expedition, based upon the indications of the document found in the keg that was thrown up on the shore at St. George, was to carry off Thomas Roch ere his engines were completed.  The French inventor having been recovered—­without forgetting Engineer Simon Hart—­he was to be handed over to the care of the Bermudan authorities.  That done, there would be nothing to fear from his fulgurator when the island was attacked.

When, however, the Sword had been given up for lost, another expedition of a different kind, was decided upon.

The time that had elapsed—­nearly eight weeks—­from the date of the document found in the keg, had to be taken into consideration.  It was thought that during the interval, Ker Karraje might have gained possession of Roch’s secrets.

An entente concluded between the maritime powers, resulted in the sending of five warships to Bermudan waters.  As there was a vast cavern inside Back Cup mountain, it was decided to attempt to bring the latter down like the walls of a bastion, by bombarding it with powerful modern artillery.