ning may set us on fire. On the other hand, the force of the squall might precipitate us to the ground if we made fast the grapnel to the top of a tree."
"Then what is to be done?"
"We must keep the "Victoria" in a middle zone between the earth and the perils of the sky. We have a sufficient quantity of water for the blow-pipe, and our 200 lbs. of ballast is intact."
"We are going to sit up with you," said the Scot.
"No, my friends; put the provisions under cover and go to bed. I will call you if necessary."
"But, sir, why will you not take some rest yourself, since nothing threatens us yet?"
"No, thank you, my lad, I would rather watch. We are motionless, and if circumstances do not change we shall find ourselves in the same place to-morrow."
"Good-night, sir."
"Good-night, if that be possible."
Kennedy and Joe then lay down, and the doctor remained by himself—alone in space. Nevertheless, the clouds insensibly descended and the darkness became profound.
The black arch of heaven spread across the terrestrial globe as if about to overwhelm it.
Suddenly a vivid flash lit up the gloom; the opening in the cloud had scarcely closed when a terrific peal of thunder shook the depths of the sky.
"Get up, get up!" cried Ferguson. The two sleepers, roused by the appalling thunder-crash, held themselves in readiness to execute his orders.
"Are you going down?" asked Kennedy.
"No; the balloon would never hold out there. Let us ascend before the rain comes and the wind gets up." And he rapidly urged the flame of the blow-pipe.
Tropical storms are developed with a rapidity proportionate to their violence. A second flash broke the cloud, and was immediately followed by twenty others. The sky was radiant with electric sparks, which shriveled up under the heavy drops of rain.
"We have delayed too long," said the doctor. "We must now pass through a belt of fire with our balloon filled with inflammable air."
