"He must hab got a shock from de dynamo!"

Andy jumped from his bunk and hurried to the engine room. There, as the negro had described, Professor Henderson was lying white and senseless on the floor.

The old hunter stooped over the inventor and felt of his heart.

"He is alive!" he exclaimed. "His heart beats! We must carry him to a bunk!"

Aided by Washington, Andy carried the professor to the sleeping room, where he was made comfortable in one of the beds. The captain was so near death that he could not be seen to breathe, and only the faint flutter of his heart told that life existed.

"We're lost!" cried Washington. "If he dies we'll never get back home again. He is de only one dat knows how to mix de chemicals for de gas!"

This was alarming news. Without the mysterious vapor the ship would not keep afloat long, nor could it be worked back from the desolate land of ice and snow. How much of the gas was left no one knew.

"Did he ever get a shock like this before?" asked the hunter of Washington.

"Once, but not so strong."

"What did you do for him? What medicine did he take?"

"Glory! Glory!" shouted the negro, jumping up and down in his excitement. "I remembers it now. Wait a second!"

He hurried to the engine room, and came back in a little while with a small bottle.

"Perfessor done say," he began, "dat if eber I seed him senselike, when he done gone and got a shock from de 'lectrisit.i.teness, I was to gib him two spoons full ob dis."

Andy took the bottle, which contained a red liquid. Bill got a spoon from the locker where the dishes were kept. With hands that trembled the old hunter poured out some of the fluid. Then, with Jack's help he forced open the inventor's mouth and put the medicine in.

"I hope it works!" murmured Andy.

He poured out a second spoonful. This was administered to the unconscious man. In a few seconds his face that had been pale showed a little color. His chest expanded as he drew a long breath. Then the old inventor opened his eyes and asked faintly:

"What happened? Where am I?"

"You are all right now," spoke Andy in a gentle voice. "You are out of danger I hope, and safe on the _Monarch_."

"Is the airship all right?" asked the captain eagerly.

"Yes, and sailing along like a bird," was the answer. In fact every one had forgotten that the craft was forging ahead, and that all the machinery was working.

A look of relief crossed Professor Henderson's face, and he sat up.

"I remember now," he said. "I was adjusting the dynamo, and I touched a live wire. The current was very strong. It is a wonder I was not killed.

But how did you bring me around again?"

"Washington happened to remember some medicine you had told him to use in emergencies."

"Oh, yes: I'm glad I had some on board. It is a remedy for those shocked with electricity. But I must see to the machinery."

"No, you must not," said Andy firmly. "You are too weak to get up yet, and you have a bad burn on your hand."

"All right," agreed Amos Henderson, for he felt weak and sick from the shock. "Some one had better see to the steering now," he added, and then he leaned back in the bunk and closed his eyes.

Jack ran to the conning tower. He found that the ship, under the influence of a strong wind, was going due west, instead of to the north.

He shifted the steering wheel and brought the _Monarch_ on her course again, pointing to the north pole. Then he called for Mark, and the two boys arranged that between them they would run the ship until Professor Henderson recovered.

Andy and Washington, who were watching beside the professor's bunk, where he reclined, seemingly in a deep slumber, were startled as he suddenly sat upright.

"Hark!" the old man exclaimed. "Listen! Do you hear it?"

"Hear what?" asked the hunter, in a soothing tone, wishing to humor the sick man.

"Do you not hear a terrible rushing, roaring wind? The ship! The ship is in danger!"

The thrilling words sent a chill to the hearts of the watchers. There was no sign of a storm. In fact it was strangely quiet outside, the only noise heard being that of the engines of the ship.

"His mind wanders," said Andy.

He had no sooner spoken than a cry from Jack, who with Mark was in the steering tower, startled them. His voice ran out through the cabins as he cried:

"A whirlwind! A whirlwind! We are running straight into a whirlwind!"

CHAPTER XIV

TOSSED BY A TORNADO

"Shut down de engines!" cried Washington.

"Lower the ship!" exclaimed Mark, who had run back from the tower.

"Close to the earth we may escape the wind!"

"Is it headed toward us?" asked Andy.

"Straight," answered Mark. Jack tried to steer to one side, but the currents of air sucked the ship right back into the path again!

"The captain knew more than we gave him credit for," muttered the hunter. "He heard the storm coming."

The air, that had been so strangely quiet, now vibrated with a curious humming. It seemed to make the whole ship tremble. Then, just as the craft began to settle down, the upward pulling force of the gas being lessened under Washington's manipulations, there came a terrible roaring. The wind howled like a thousand demons seeking to tear the _Monarch_ to pieces.

"It's a regular tornado!" cried Andy.

Then the storm picked the downward-falling ship up as if it had been a feather and tossed the craft into the air. The adventurers were in a sad plight.

There was nothing to be done. The forces of nature were ten times stronger than those of man. To start the engines and try to run the ship out of the grasp of the wind would only mean to strain the craft to a dangerous point. There was but one thing to do, to run before the tornado, as ships on the sea scud before the gale. In this way the airship might be saved, if it was not dashed down to earth.

As soon as this plan manifested itself to be the best one, Washington stopped drawing gas from the bag. He wanted to keep the ship as high as he could. Jack still held his place in the conning tower, but he could do nothing to guide the craft, and it would have been folly to attempt it, so fearful was the force of the wind.