"Ain't that what you expected at the south pole?" asked Andy. "I thought it was hot at the south pole and cold at the north."

"That's what lots of people imagine," said the professor, "but except for the open sea, which I have proved does exist, I guess it's just as cold at the south as at the north, especially in the winter. We have struck the summer season."

"And a mighty warm one at that," observed Jack. "Whew! I've got to take off my coat."

Indeed it was getting uncomfortably warm in the ship, and the adventurers who had dressed in thick clothing to guard against the rigors of the icy climate, soon had to lay aside many of their garments.

"No wonder!" exclaimed Mr. Henderson, as he looked at a thermometer. "It is eighty degrees in here!"

"Worse than workin' in a hay field," observed Bill, as he wiped the beads of perspiration from his forehead.

"Let us see what sort of water we are traveling through," suggested the professor, as he again turned off the lights in the cabin so that a view could be had from the bull's-eyes.

Wondering what would meet their gaze the adventurers peered out of the small circular windows. At first they could hardly believe their eyes.

There, right before them, the sea was bubbling as if it was an immense tea kettle. Steam formed on the gla.s.s, and big clouds of vapor could be seen. The atmosphere of the cabin became almost unbearable.

"We are in the midst of a boiling hot ocean!" cried the professor.

"Are we sailing through hot water?" asked Andy.

"I should say so, from the feel of it," answered Mr. Henderson. "Put your hand on the side of the cabin."

Andy laid his fingers against the steel plates. He drew back.

"I burned myself!" he exclaimed.

"What are we to do?" cried Jack.

"Get out of this by all means!" exclaimed the inventor. "If we stay in this hot ocean we will be boiled alive like fishes in a pot. Send the ship up, Washington!"

Indeed it was high time. The thermometer marked one hundred and ten degrees, and was rising. The interior of the _Porpoise_ was like that of a steam laundry three times heated. Stripped to their undergarments the adventurers were obliged to lie down on the floor of the cabin where it was a little cooler.

It was all Washington could do, used as colored people are to the heat, to go into the engine room, and start the machinery that emptied the tanks, so as to allow the ship to mount to the surface.

The _Porpoise_ began to rise slowly, and to the suffering men and boys it seemed that she never went up so reluctantly. The heat was becoming unbearable. They could hear the water bubbling even through the steel sides of the submarine.

CHAPTER x.x.x

CONCLUSION

Could they live to reach the surface? was the thought in the mind of every one. The heat was terrific. They were breathing in gasps.

Professor Henderson went to the water tank, thinking to throw some of the fluid over himself and his companions, but he found it so warm that it almost burned his hand.

"Keep up your courage!" exclaimed the inventor. "We will soon be at the top!"

Almost as he spoke the _Porpoise_ bounded from the waves, and fell back in a splash of foam on the surface of the billows. They were at the surface.

The professor rushed for the manhole and soon opened it. He crawled out on the deck, followed by the others. They breathed in deep breaths of the fresh air.

The submarine continued to sail on. Every minute the sea seemed to boil more violently, until at last the waves were covered with a cloud of steam, through which it was difficult to observe where they were going.

"Hadn't we better turn back," suggested Mark.

"Our only hope is to press on," replied Mr. Henderson. "We may cross this zone of boiling water soon."

He went into the conning tower to make an observation. He came on the deck the next minute, very much excited.

"What's the matter? Are we sinking?" asked Andy.

"We are directly over the south pole!" exclaimed the professor. "We have reached the goal! We have come to the spot hundreds of men have tried to reach! It has been left for us to succeed. Look at the deflecting needle!"

They crowded into the conning tower to note it. The slender hand of steel stood straight up and down, indicating that the ship was over the south pole, one of the two chief centres of magnetism of the earth.

"If we only dared stop to make some scientific notes and observations,"

said the professor, "we could render much valuable aid to the seekers after truth. But it would be sure death to stay in the boiling water!"

"I guess we'd better be getting out of this if we want to reach home alive," spoke Andy.

Indeed they were all suffering very much, for the heat from the water was awful.

"Speed her up, Washington!" called the professor. "We must get out of here!"

"Which way shall I steer?" asked the colored man.

"Straight ahead. We are now bound north!"

"Bound north!" cried Jack.

"Certainly," answered the professor. "We have pa.s.sed over the exact spot where the south pole is. The deflecting needle is beginning to tilt again. The compa.s.s is indicating a northerly direction. You know that after you go as far south as you can, you have to begin to go back north. Well, we have gone as far south as we can. Now we are going north. We have turned the southern end of the globe, and are on our way back."

For several hours the _Porpoise_ continued along on top of the water. By degrees, as they left the vicinity of the boiling ocean, it became cooler. The water ceased to seethe and bubble, and Jack found, on experiment, that he could bear his hand in it.

"Hurrah!" he cried, "we are safe now."

"Next we'll have to prepare to freeze to death," spoke Mark. "It's either one extreme or the other this trip. But we've had lots of fun and excitement."

"Plenty of the last," agreed Jack.

On and on went the submarine. Once it was out of the range of the terrible heated zone, the atmosphere rapidly cooled, until the adventurers were glad to don their heavy garments again.

"This marks the ending of the first half of the voyage," announced the professor. "Now we are going back. We have accomplished something no other living man has done and I am proud of it. Proud of all of you, and proud of the ship!"

Several hours later, when it was deemed safe, the _Porpoise_ was sunk beneath the waves, and once more she speeded along through the water at a fast speed. The ship seemed to know she was going home, for never had she made better time.