The time has come.

"Thomas Roch!" Engineer Serko cries, and points to the cruiser.

The latter is steaming slowly towards the northwestern point of the island and is between four and five miles off.

Roch nods a.s.sent, and waves them back from the trestle.

Ker Karraje, Captain Spade and the others draw back about fifty paces.

Thomas Roch then takes the stopper from the phial which he holds in his right hand, and successively pours into a hole in the rear-end of each engine a few drops of the liquid, which mixes with the fusing matter.

Forty-five seconds elapse--the time necessary for the combination to be effected--forty-five seconds during which it seems to me that my heart ceases to beat.

A frightful whistling is then heard, and the three engines tear through the air, describing a prolonged curve at a height of three hundred feet, and pa.s.s the cruiser.

Have they missed it? Is the danger over?

No! the engines, after the manner of Artillery Captain Chapel's discoid projectile, return towards the doomed vessel like an Australian boomerang.

The next instant the air is shaken with a violence comparable to that which would be caused by the explosion of a magazine of melinite or dynamite, Back Cup Island trembles to its very foundations.

The cruiser has disappeared,--blown to pieces. The effect is that of the Zalinski sh.e.l.l, but centupled by the infinite power of Roch's fulgurator.

What shouts the bandits raise as they rush towards the extremity of the point! Ker Karraje, Engineer Serko, and Captain Spade remain rooted to the spot, hardly able to credit the evidence of their own eyes.

As to Thomas Roch, he stands with folded arms, and flashing eyes, his face radiant with pride and triumph.

I understand, while I abhor his feelings.

If the other warships approach they will share the same fate as the cruiser. They will inevitably be destroyed. Oh! if they would but give up the struggle and withdraw to safety, even though my last hope would go with them! The nations can consult and arrive at some other plan for destroying the island. They can surround the place with a belt of ships that the pirates cannot break through and starve them to death like so many rats in a hole.

But I know that the warships will not retire, even though they know they are going to certain death. One after the other they will all make the attempt.

And I am right. Signals are exchanged between them. Almost immediately clouds of black smoke arise and the vessels again advance.

One of them, under forced draught, distances the others in her anxiety to bring her big guns quickly into action.

At all risks I issue from my hole, and gaze at the on-coming warship with feverish eyes, awaiting, without being able to prevent it, another catastrophe.

This vessel, which visibly grows larger as it comes nearer, is a cruiser of about the same tonnage as the one that preceded her. No flag is flying and I cannot guess her nationality. She continues steaming at full speed in an effort to pa.s.s the zone of danger before other engines can be launched. But how can she escape them since they will swoop back upon her?

Thomas Roch places himself behind the second trestle as the cruiser pa.s.ses on to the surface of the abysm in which she will in turn soon be swallowed up.

No sound disturbs the stillness.

Suddenly the rolling of drums and the blare of bugles is heard on board the warship.

I know those bugle calls: they are French bugles! Great G.o.d! She is one of the ships of my own country's navy and a French inventor is about to destroy her!

No! it shall not be. I will rush towards Thomas Roch--shout to him that she is a French ship. He does not, cannot, know it.

At a sign from Engineer Serko the inventor has raised the phial.

The bugles sound louder and more strident. It is the salute to the flag. A flag unfurls to the breeze--the tricolor, whose blue, white and red sections stand out luminously against the sky.

Ah! What is this? I understand! Thomas Roch is fascinated at the sight of his national emblem. Slowly he lowers his arm as the flag flutters up to the mast-head. Then he draws back and covers his eyes with his hand.

Heavens above! All sentiment of patriotism is not then dead in his ulcerated heart, seeing that it beats at the sight of his country's flag!

My emotion is not less than his. At the risk of being seen--and what do I now care if I am seen?--I creep over the rocks. I will be there to sustain Thomas Roch and prevent him from weakening. If I pay for it with my life I will once more adjure him in the name of his country. I will cry to him:

"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 pa.s.sed the zone and they cannot return her fire. Sh.e.l.ls 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 pa.s.sage.

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."