Part 17 (1/2)

Was.h.i.+ngton set the big screw to revolving in the opposite direction. The _Porpoise_ shook and s.h.i.+vered but the mud held her fast.

”We must have gone in pretty deep,” commented Amos Henderson. ”Luckily it was soft mud instead of a rocky reef or we'd have damaged the s.h.i.+p beyond repair.”

For several minutes the engines were kept on the reverse, but all to no purpose. The sticky mud was like glue in its holding power and the s.h.i.+p had buried her prow deep into it.

”I guess we'll have to dig our way out,” said the professor, after taking a careful view of the big mud bank from the conning tower.

”Was.h.i.+ngton, get out the diving suits and the spades.”

”Are we really going out in the water to dig?” asked Tom.

”Of course,” said Mr. Henderson. ”You'll be as safe as in the s.h.i.+p, wearing one of my diving suits. We'll all have to help, for it will be quite a task.”

The queer suits were brought out, and the reservoirs in the helmets were filled with compressed air. It was decided to have Was.h.i.+ngton remain within the _Porpoise_, to watch the machinery and start the engine when the digging was partly done, in order to see if the s.h.i.+p would not pull herself free when some of the mud had been removed from the prow.

”And we may need Was.h.i.+ngton for another purpose,” said the professor.

”What for?” asked Mark.

”Well, he'll have to stay by the diving tank, to let us in quickly in case of emergency.”

”Do you think there'll be an emergency?” asked Jack.

”You never can tell,” was the answer. ”We are in deep water, and I don't want any accidents to happen.”

In a few minutes all save Was.h.i.+ngton were in their diving suits and ready to go out and walk on the bottom of the sea. They entered the tank, the door was closed, and then water was slowly admitted from the ocean. When the tank was full, led by the professor, they stepped out on the muddy floor of the ocean.

At first the pressure of the water at so great a depth bothered them.

But, as we know, the diving suits were reinforced with plates of steel, and so strong that little more than an extra weight of water was noticed. They soon became used to it. Each one carried a spade, while the professor, Andy and the boys each had, slung about their necks by straps, one of the electric guns.

Cautiously they walked toward the big mud bank. They had to go slowly because of the weight of the water above them, and because they might at any minute step into some muck hole and sink down. Fortunately, however, they found there was a firm bottom right up to where the bank of mud reared upward.

Turning on the electric lights in their helmets, the voyagers were able to see quite distinctly. The _Porpoise_ had rammed her nose into the under-water hill for a distance of about ten feet. It was going to be no easy matter to get her free, but the divers lost no time.

Vigorously they attacked the big hill of mud. They dug their spades in and tossed the earth to one side. It was a strange place to work. At first the weight of water hampered every one, but they soon became used to it and were able to proceed more rapidly.

From the conning tower Was.h.i.+ngton kept watch of their progress. When they had gone in about five feet he started the engines, hoping the _Porpoise_ might now pull herself free. But the mud still held.

By signs, for it was of course impossible for any one to hear or speak, attired as they were in helmets and suits, the professor motioned that they must dig deeper.

Once more they attacked the big mud bank with their shovels. Farther and farther they went into the muck until it seemed that the nose of the submarine must be free. But when Was.h.i.+ngton started the engines it was obvious that the s.h.i.+p was still held.

Again the digging was resumed. All at once, while every one was wielding his spade to best advantage, a shadow seemed to cover the water. It loomed up large and black, and the professor stopped and gazed upward.

What he saw made him drop his spade and grab the gun that was about his neck.

Floating in the water above the diggers, were three immense sharks.

Their cruel mouths were partly open, showing three rows of big teeth, and they were slowly turning over on their backs to make a sudden rush and devour the men and boys. Owing to the peculiar shape of its maw a shark can not bite until it turns over.

The professor motioned for Bill and Tom to move behind him, and signalled for Jack, Mark and Andy to stand close with their weapons ready.