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: