is time. Giving way at last to his rising
fury, he stamped on the ground and almost screamed--

"Great God! you insolent scoundrel! Why do you ask me questions when
you know the answers as well as I do, and better? Yes, we have got
one of your diabolical ships of the air, and we will build a fleet
like it and hunt you from the world!"

"All in good time, my dear sir," replied Mazanoff ironically. "When
you have found a place in which to build them that we cannot blow off
the face of the earth before you get one finished. Meanwhile, let me
beg of you to keep your temper, and to remember that there is a lady
present. That girl standing yonder by the gun was once stripped and
flogged by Russians calling themselves men and soldiers. Her fingers
are itching to make the movement that would annihilate you and every
one standing near you, so pray try keep your temper; for if we fire a
shot the air-ships up yonder will at once open fire, and not stop
while there is a stone of that building left upon another. Ah! here
comes the Professor."

As he spoke the man of science advanced, looking wonderingly at the
air-ship. Mazanoff made a sign to the old officer to keep silence,
and continued in the same polite tone that he had used all along--

"Good evening, Professor! I have come to ask you whether you have yet
made any experiments on the contents of the shell and the two
cylinders that were given to you for examination?"

"I must first ask for your authority to put such an inquiry to me on
a confidential subject," replied the Professor stiffly.

"On the authority given me by the power to enforce an answer, sir,"
returned the Terrorist quietly. "I know that Professor Volnow will
not lie to me, even at the order of the Tsar, and when I tell you
that your refusal to reply will cost the lives of every one here, and
possibly involve the destruction of Petersburg itself, I feel sure
that, as a mere matter of humanity, you will comply with my request."

"Sir, the orders of my master are absolute secrecy on this subject,
and I will obey them to the death. I have analysed the contents of
one of the cylinders, but what they are I will tell to no one save by
the direct command of his Majesty. That is all I have done."

"Then in that case, Professor, I must ask you to surrender yourself
prisoner of war, and to come on board this vessel at once."

As Mazanoff said this the _Ariel_ dropped to within ten feet of the
ground, and a rope-l