"Is she for sale?" asked Captain Wackford.

"No, thank you," replied Mr. Henderson with a laugh.

"Because if she is I'll give you free pa.s.sage to England with her, on my ship," went on the commander. "My government would give a fortune for a boat that can do what yours does."

"It is not for sale," repeated Mr. Henderson, "but I have some one on board who would appreciate a free pa.s.sage to England, or any northern port."

"Who is it?" asked Captain Wackford.

"A Mrs. Johnson and her daughter."

CHAPTER XXIII

CAUGHT IN AN ICE FLOE

Mr. Henderson soon explained the finding of the lady and the little girl, and Captain Wackford readily agreed to give them pa.s.sage to New York, as the _Sylph_ was to call at that port.

So Nellie and her mother were put aboard the warship, after bidding farewell to the captain and crew of the submarine. Mr. Henderson and the boys promised to write to them as soon as they got back from their voyage to the south pole, and, amid a chorus of good-byes the _Porpoise_ resumed her journey.

For several days the submarine forged to the south, and the weather became noticeably cooler. Some of the nights were chilly, and those on watch were glad of the heavy coats they had brought along.

One morning, after a week of travel, when no interruptions had occurred by reason of accidents, old Andy came up on deck, and sniffing the air, said:

"We'll sight ice before night, or I'm a Dutchman."

"What makes you think so?" asked Jack.

"I can smell it," replied the hunter, whereat Jack, and Mark who had joined him, laughed.

"That is no joke," put in Professor Henderson, who, coming up the companionway heard what was said. "Old sea captains will tell you they can smell an iceberg long before they can see it."

"I don't claim to be a sea captain," said Andy, "but I once was on a whaling voyage and I learned to sniff ice in the air. I saved the ship from collision with a berg once."

"Let me see," began the inventor as the adventurers sat about the supper table after the meal was finished, "who have the watches on deck to-night?"

"Washington first and Bill second," replied Jack looking at the chart.

"Keep a sharp watch for the icebergs," advised the captain. "If you feel a sudden chill in the air, and see something white, stop the engine at once and call for me."

When the _Porpoise_ had been put in shape for the night, and the company, tired out from their labors over a general "house cleaning"

which Captain Henderson had insisted on, went to bed, Washington took his place in the conning tower.

It was quite cold, but as the temperature for several days past had been steadily falling, nothing was thought of it.

"I guess I'll git out my fur-lined sealskin coat," said the colored man to himself as he felt the chill night air, that seemed to increase in frigidity along about eleven o'clock. He went to the cabin to get his overcoat, and, returning on deck prepared to spend the rest of his hour of watch in ease and comfort. He stretched out on the bench in the conning tower, noted that the machinery was working right and that the proper course was being steered, and then he let his thoughts drift to the many adventures he and his employer had gone through of late, and also while on the trip "Through the Air to the North Pole."

Washington gave one frightened, startled look, in a few minutes, so comfortable had he fixed himself, but happening to look forward through the gla.s.s-covered porthole of the tower, he saw something that made the cold chills run down his back.

There, right in front of the _Porpoise_, and not a cable-length away was a tall, mysterious, white thing which was shimmering in the pale light of the moon that had lately risen.

Washington gave one frightened, startled look, and then, with a tongue that could hardly move, he yelled out:

"De ghost! De ghost! He'll git me suah!"

Then the colored man made a dive for the stairway leading to the cabin, but missed it and brought up with a crash on the steel floor of the conning tower.

"What is it?" called Professor Henderson, springing out of his bunk.

"De ghost!" wailed Washington from the huddled up heap he was in.

"Catch him!" yelled the captain.

"I dasn't," moaned Washington.

The next instant the ship quivered from stem to stern. There was a terrible shock, followed by a grinding, crashing sound. Then the craft seemed to be pressed down by some great weight. It heeled over to one side, and the water began to pour down the open man-hole.

"Quick! Clamp on the covers!" shouted Mr. Henderson as he felt the sea dashing into the interior of the boat.

Jack and Mark sprang to obey. It took all their strength, for the water was running in like a mill-race.

"What has happened?" asked Andy, as he tried to climb up the companionway ladder, that was tilted backward.

"I guess we've hit your iceberg!" cried Mr. Henderson.

"I knew I smelled the frozen stuff," replied the old hunter.

They got the covers on the manhole only just in time and they all crowded into the cabin, while Jack switched on the electric lights.

"Is the ship damaged?" asked Mark.

"I think not," replied Mr. Henderson. "But we are sinking. Look at the depth gage."

The hand on the clock-face was moving slowly around. From ten it went to twenty feet, then to thirty and kept going until it stood at seventy.

"Look to the air tanks," ordered Mr. Henderson to Washington, who, by this time had recovered from his fright. "See if they are all right."

The colored man came back in a few minutes and reported that the supply of compressed atmosphere was safe and that there was plenty of it.

"That's good," remarked Mr. Henderson. "Whatever else happens we can breathe for a while."

"But what has happened?" asked Andy.

"I think the top part of an iceberg toppled down on us," was the reply.

"You know about nine-tenths of a berg is under water. Sometimes there is a warm current of the ocean underneath the ice, and it melts. Then it becomes top-heavy and tilts over. One of that sort must have caught us, and has shoved us down into the sea."