o enjoy
them outside?"

"That, Mr. Hart, is a matter that does not trouble him a little bit!
This man of genius thinks nothing of the future: he lives but in the
present. While engines are being constructed from his plans over
yonder in America, he is preparing his explosive with chemical
substances with which he has been abundantly supplied. He! he! What an
invention it is, this autopropulsive engine, which flies through
the air of its own power and accelerates its speed till the goal is
reached, thanks to the properties of a certain powder of progressive
combustion! Here we have an invention that will bring about a radical
change in the art of war."

"Defensive war, Mr. Serko."

"And offensive war, Mr. Hart."

"Naturally," I answer.

Then pumping him still more closely, I go on:

"So, what no one else has been able to obtain from Thomas Roch--"

"We obtained without much difficulty."

"By paying him."

"By paying him an incredible price--and, moreover, by causing to
vibrate what in him is a very sensitive chord."

"What chord?"

"That of vengeance!"

"Vengeance?--against whom?"

"Against all those who have made themselves his enemies by
discouraging him, by spurning him, expelling him, by constraining
him to go a-begging from country to country with an invention of
incontestable superiority! Now all notion of patriotism is extinct in
his soul. He has now but one thought, one ferocious desire: to avenge
himself upon those who have denied him--and even upon all mankind!
Really, Mr. Hart, your governments of Europe and America committed a
stupendous blunder in refusing to pay Roch the price his fulgurator is
worth!"

And Engineer Serko describes enthusiastically the various advantages
of the new explosive which, he says, is incontestably superior to any
yet invented.

"And what a destructive effect it has," he adds. "It is analogous to
that of the Zalinski shell, but is a hundred times more powerful, and
requires no machine for firing it, as it flies through the air on its
own wings, so to speak."

I listen in the hope that Engineer Serko will give away a part of the
secret, but in vain. He is careful not to say more than he wants to.

"Has Thomas Roch," I ask, "made you acquainted with the composition of
his explosive?"

"Yes, Mr. Hart--if it is all the same to you--and we shall shortly
have considerable quantities of it stored in a safe place."

"But will there not be a great and ever-impend