"Come, Professor, there is no time to be lost. I shall give the order to fire in one minute from now."
He took out his watch, and began to count the seconds. Ten, twenty, thirty passed and the Professor stood irresolute. Two of the Ariel's guns pointed at the gables of the Arsenal, and two swept the crowded space in front.
Konstantin Volnow knew enough to see clearly the frightful slaughter and destruction that twenty seconds more would bring if he refused to give himself up. As Mazanoff counted "forty" he threw up his hands with a gesture of despair, and cried—
"Stop! I will come. The Tsar has as good servants as I am! Colonel, tell his Majesty that I gave myself up to save the lives of better men."
Then the Professor mounted the ladder amidst a murmur of relief and applause from the crowd, and, gaining the deck of the Ariel, bowed coldly to Mazanoff and said—
"I am your prisoner, sir!"
The captain of the Ariel bowed in reply, and stamped thrice on the deck. The fan-wheels whirled round, and the air-ship rapidly ascended, at the same time moving diagonally across the quadrangle of the Arsenal.
Scarcely had she reached the other side when there was a tremendous explosion in the north-eastern angle of the building. A sheet of flame shot up through the roof, the walls split asunder, and masses of stone, wood, and iron went flying in all directions, leaving only a fiercely burning mass of ruins where the gable had been.
The Professor turned ashy pale, staggered backwards with both his hands clasped to his head, and gasped out brokenly as he stared at the conflagration—
"God have mercy on me! My laboratory! My assistant—I told him"—