FIRE ON BOARD
The professor jumped past Washington and hurried into the room where the tanks were kept, carrying the reserve supply of air for breathing when the ship was under water. A loud hissing told that the leak was a large one.
"Quick! Bring me some tools and a steel plug," shouted the captain.
Mark hurried in with the things the professor wanted. But before the plug could be put in the hole the air stopped hissing.
"The leak is fixed!" cried Jack.
"No," said the professor in a strange voice.
"But the air no longer rushes out."
"For a good reason, there is no longer any air to rush out. It is all gone!"
"Do you mean to say that all the reserve stock has been lost?" exclaimed Andy.
"I fear so. The leak must have been a bad one. The air was stored in tanks under pressure, and, as you know, we released it as we needed it. Now it is all gone."
"All? Then we shall smother," said Jack, and his voice trembled.
"Not at once," went on Mr. Henderson in a calm voice. "There is enough air in the entire ship, including that which has leaked from the tanks to last us five hours. After that——" he paused and looked at his watch.
"Well?" asked Andy. "After that?"
"There is enough stored in the small tanks of the diving suits to last another two hours, perhaps. Seven hours in all."
"Then what?" asked Mark.
"We shall smother to death," said the professor in a low tone. "That is," he went on, "unless before that time we can raise the Porpoise to the surface of the sea and get a fresh supply of air."
"Then we must work to raise the ship," put in Bill. "Let' get out and see if we can't cut through the sea weed."
"It would be useless," said Mr. Henderson. "We can only depend on the power of the ship herself. But do not be discouraged. We may escape. Come, Washington, start the engine again. By keeping it going constantly we can, perhaps, break loose from the grass. It is our only hope."
Steadily the machinery worked. It might as well have remained stationary, however, as far as any noticeable effect was made on the boat's progress. The grass of the Sargasso Sea held the Porpoise in a firm grasp.
Four hours passed. There was nothing to do but wait and see what would happen. It all depended on the engines. Silently the navigators of the realms under the ocean sat and hoped. Now and then the professor would go to the engine room to adjust the machines.
The atmosphere in the cabin was growing noticeably heavier. The boys' heads began to ring with strange noises, and there was a tightness across their chests. The lack of fresh air was beginning to tell.
"We might as well use that in the diving suit reservoirs," remarked the professor. "We will feel better, at least for a little while."
The helmets of the suits were brought in, and the vapor released from the small tanks. A change was at once noticed. The old stale air in the cabin was forced out of the exhaust pipes, and the fresh took its place. Every one felt better.
Faster and faster revolved the big screw. The ship vibrated more and more. Yet it did not move, nor did it rise. The crew were still prisoners beneath the water.
For an hour or so conditions were fairly comfortable. Then the same unpleasantness was experienced as was noticed before.
"If we could only open a window," sighed Mark, "and let in a lot of fresh air, how nice it would be."
The air rapidly became more foul. Soon Washington was gasping for breath. Tom and Bill showed signs of uneasiness.
"Lie down on the floor," counseled the professor. "You will find the air a little fresher down there."
They all did as he advised, the inventor himself stretching out at full length. A little relief was experienced.
They knew it could not last long. Even the professor seemed to have given up hope. The engine was not going to free the ship in time to save the lives of those on board.
Washington crawled to the engine room, as some of the bearings needed oiling. The professor seemed in despair. He opened one of the slides that covered the glass bulls eye windows. Then he turned off the electric lights. The opening was black, showing that the sea of grass still surrounded them. With a groan Mr. Henderson turned aside. The last hope was gone. He sank down on the floor of the darkened cabin.
Just then Mark happened to look at the bull's-eye. He saw a glimmer of light. Then he noticed several fishes swimming about. The water was clear. The grass had disappeared from the vicinity of the window.
"Look!" cried Mark to the professor.
The inventor peered forth. As he did so he uttered a cry. Then he staggered rather than ran to the engine room.
"What are you doing?" he called to Washington.
"I jest let some ob de sulphuric acid out ob de storage battery tank," replied the colored man.
"That's it! That's it!" exclaimed the professor. "Quick, let some more out, Washington. Let out all there is in that tank. It will save our lives."
Wonderingly Washington obeyed. The air in the ship was growing more foul every second. It was hard to breathe even on the floor, and all were gasping for breath. A few minutes more and they would all become unconscious and death would come in a little while if the air was not freshened.
The professor staggered back to the main cabin. He looked out of the bull's-eye windows. Then he exclaimed:
"See, it is getting lighter! Thank Heaven we are saved!"
The next instant the ship began to move backward. Then with increasing speed it pulled out of the grip of the long grass, and in another minute was floating on top of the water, at the edge of the Sargasso Sea.
"Quick! Open the man hole cover!" said Amos Henderson.
Washington threw back the lever cams, and in rushed the fresh air. It was a blessed relief from the terrible oppressiveness of the foul atmosphere of the boat. They all breathed deeply, and, in a few minutes the effects of their long imprisonment had passed off.
They went out on the small deck. It was getting dusk, and the reflection of the red sunset shone brightly on the heaving water.
"I 'spected I'd neber see dis again," said Washington. "Thought suah I was a gone chicken!"
"We had a most fortunate escape," said the professor. "You did the trick for us when you let the acid run from that tank into the sea. It mingled with the water and burned or ate through the stems of the grass so they no longer held the ship. I saw what had happened as soon as I looked out of the bull's-eye, and that's why I had you turn out all the acid you could. It was just as if liquid fire had touched the sea weed and burnt it off."
"Golly!" exclaimed Washington. "Fust I know I'll be a perfessor myself!"
Supper was eaten with the ship on the surface of the ocean, for it was impossible to go below until the leak in the air tanks had been repaired. Work was begun on this the next day, and though it proved a difficult job it was accomplished by Mr. Henderson and the boys.
There were several minor repairs to be made to the machinery, and it was a week before all was in readiness for another descent beneath the waves. In the meanwhile the craft had moved slowly southward on the surface, where no very great speed was possible.
Toward evening, on the seventh day after their adventure with the Sargasso Sea, the travelers closed the man hole, and with air tanks well filled slowly sank beneath the waves. Supper was eaten at a depth of sixty feet, and after the meal, while Washington was washing the dishes, the others sat and looked out through the bull's-eyes at the big fishes which floated past.
"I wouldn't like to catch one of them air things on my hook an' line," observed Bill, as a particularly large fish went past. "I reckon I'd have trouble landin' him."
"More likely he'd pull you in," said Mark.
For several minutes they watched the strange procession of deep-sea life. Presently Jack, who was sitting near the engine room door, sprang up. At the same instant there was the sound of an explosion.
"What's the matter?" cried the professor.
"Come quick!" yelled Washington.
"It's a fire!" yelled Jack. "One of the electrical fuses has blown out, and the ship is on fire!"