He recognized the peak at a glance as being that of the _Ella_, and knew therefore that the wall at this part skirted the right bank of the Neuse.

The Count d'Artigas' whole attention was concentrated upon the French inventor. The latter's health appeared to have suffered in no way from his eighteen months' confinement; but his queer attitude, his incoherent gestures, his haggard eye, and his indifference to what was passing around him testified only too plainly to the degeneration of his mental faculties.

At length Thomas Roch dropped into a seat and with the end of a switch traced in the sand of the alley the outline of a fortification. Then kneeling down he made a number of little mounds that were evidently intended to represent bastions. He next plucked some leaves from a neighboring tree and stuck them in the mounds like so many tiny flags. All this was done with the utmost seriousness and without any attention whatever being paid to the onlookers.

It was the amusement of a child, but a child would have lacked this characteristic gravity.

"Is he then absolutely mad?" demanded the Count d'Artigas, who in spite of his habitual impassibility appeared to be somewhat disappointed.

"I warned you, Count, that nothing could be obtained from him."

"Couldn't he at least pay some attention to us?"

"It would perhaps be difficult to induce him to do so."

Then turning to the attendant:

"Speak to him, Gaydon. Perhaps he will answer you."

"Oh! he'll answer me right enough, sir, never fear," replied Gaydon.

He went up to the inventor and touching him on the shoulder, said gently: "Thomas Roch!"

The latter raised his head, and of the persons present he doubtless saw but his keeper, though Captain Spade had come up and all formed a circle about him.

"Thomas Roch," continued Gaydon, speaking in English, "here are some visitors to see you. They are interested in your health--in your work."

The last word alone seemed to rouse him from his indifference.

"My work?" he replied, also in English, which he spoke like a native.

Then taking a pebble between his index finger and bent thumb, as a boy plays at marbles, he projected it against one of the little sand-heaps. It scattered, and he jumped for joy.

"Blown to pieces! The bastion is blown to pieces! My explosive has destroyed everything at one blow!" he shouted, the light of triumph flashing in his eyes.

"You see," said the director, addressing the Count d'Artigas. "The idea of his invention never leaves him."

"And it will die with him," affirmed the attendant.

"Couldn't you, Gaydon, get him to talk about his fulgurator?" asked his chief.

"I will try, if you order me to do so, sir."

"Well, I do order you, for I think it might interest the Count d'Artigas."

"Certainly," assented the Count, whose physiognomy betrayed no sign of the sentiments which were agitating him.

"I ought to warn you that I risk bringing on another fit," observed Gaydon.

"You can drop the conversation when you consider it prudent. Tell Thomas Roch that a foreigner wishes to negotiate with him for the purchase of his fulgurator."

"But are you not afraid he may give his secret away?" questioned the Count.

He spoke with such vivacity that Gaydon could not restrain a glance of distrust, which, however, did not appear to disturb the equanimity of that impenetrable nobleman.

"No fear of that," said the warder. "No promise would induce him to divulge his secret. Until the millions he demands are counted into his hand he will remain as mute as a stone."

"I don't happen to be carrying those millions about me," remarked the Count quietly.

Gaydon again touched Roch on the shoulder and repeated:

"Thomas Roch, here are some foreigners who are anxious to acquire your invention."

The madman started.

"My invention?" he cried. "My deflagrator?"

And his growing animation plainly indicated the imminence of the fit that Gaydon had been apprehensive about, and which questions of this character invariably brought on.