"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.

"which way are we headed?" asked mark, making his way back to the tower where jack was.

"almost due west," was the reply. "about two points to the south, too."

"then we are being driven away from the north pole," said mark.

"we're as helpless as kittens tied up in a sack," said andy. "if only i could do something i'd feel better. but i've got to sit here and take what comes."

the sick man stirred uneasily. then he muttered in his delirium something about the tornado that was tossing him from side to side of the bunk.

strangely enough there was nothing to the storm but wind. there was no rain or snow, and the air was remarkably clear, excepting for the darkness of the clouds. aside from the way in which the ship was blown along there was nothing to indicate that the breeze was rushing along at tempest speed. there were no trees bent to the earth, and no clouds of dust. the sky clouds kept pace with the airship.

"i wonder where we are?" asked jack, who with mark had come back from the tower.

"we'll have to guess at it," replied andy. "it would be as much as a man's life is worth to go outside and take an observation."

"don't hab to do dat," broke in washington. "see here!"

he stooped over and pulled on an iron ring that was fastened in the floor of the dining-room cabin. a section of a board came up.

"look!" exclaimed the negro pointing down. all leaned forward and saw that a heavy plate glass had been set over a hole cut through the floor of the ship. by means of this strange window one could look directly down toward the earth. jack kneeled and peered through the glass. he rose to his feet with a cry of fear.

"what's the matter?" asked andy.

"we are right over the ocean!" exclaimed the boy. "i can see immense waves not three hundred feet below! the airship must be falling and we'll be dashed into the sea!"

at these words washington ran to the engine room. he looked at the height indicator.

"we's four hundred feet in de air, an' a—we's agoin' down!" he muttered.

jack, who had followed him, saw by the instrument what the dreadful truth was. blown from her course, the monarch was now over an open polar sea, into which she might be dashed at any moment. the tornado still howled and roared outside, making it impossible to inflate the gas bag, so strong was the pressure of wind on it. and without a fresh supply of gas, the ship must fall.

there was no abatement to the tornado. the ship was tossed more violently than ever. jack peered through the floor-window again.

"we are nearer the water!" he exclaimed as he arose. "the sea is covered with icebergs. they are crashing together in the big waves. if we fall the ship will be ground to pieces in the floes!"

"try the gas machine again!" urged andy. "maybe the wind has lessened."

washington started the machine. he kept one eye on the needle of the indicator that told the gas pressure in the bag, and the other on the height register. the black pointer of the latter went lower and lower. it was now at one hundred, and kept on going down slowly, until it stood at seventy-five. soon only sixty-five feet stood between the airship and her passengers, and the angry, swirling water beneath, where the icebergs crashed and ground together.

then washington, who was ready to faint with fear and despair, gave a cry of joy. he had noticed that the height indicator stopped. at the same time the gas register showed that the vapor from the machine was entering the bag.

"glory! glory!" cried the negro. "we's saved now. de ship is goin' up, and the gas is workin' in. de wind must be goin' down!"

then, while all save professor henderson, who was still unconscious, crowded into the engine room, they saw that what washington said was true. the pressure of the wind had lessened, permitting the bag to fill with the gas. this served to lift the ship, and the pointer on the height indicator began to move upward. higher and higher went the craft, until in a few minutes the register showed six hundred feet. they had been saved from death in the sea.

"hurrah!" cried jack. "i believe the tornado has left us!"

indeed the roaring of the wind was less now. the ship was no longer violently tossed. in a few minutes the wind died away almost completely, and, aside from the rising motion, and a slight swaying, the monarch rode on an even keel. the danger was over.

"is the ship safe?" called professor henderson from his bunk.

"all safe!" exclaimed the hunter cheerfully. "we had a little blow, but it is all over, and the monarch behaved like the king she is—or, perhaps i ought to say queen, seeing that all ships are ladies. but how do you feel, professor?"

"i am much better," was the answer, showing that the medicine had done its work. "i feel hungry," he went on. "what time is it?"

"six o'clock," answered jack, looking at the dial.

"night or morning?"

"morning, i guess."

"then we'll have breakfast," said the professor with a smile.

he stepped from the bunk. as he did so there was a sudden lurch to the ship. then it began to sink suddenly.

"we are going down!" cried the captain. "what has happened?"

"the gas bag is leaking again!" shouted washington from the engine room.