They seemed to feel a great weight. It gradually lessened, however, and, in a few minutes, they saw something move in front of them. The professor pushed them gently forward.

In another instant they were walking on the bed of the ocean, having stepped from the _Porpoise_. They had gone into a locked compartment, the inner door of which had been tightly closed, after which water from outside had been gradually admitted until the pressure was equal, and then the boys and the professor had merely to emerge out into the bottom of the sea when the outer portal was swung aside by Washington, who worked the lever from inside.

The boys were in intense darkness, but, suddenly a light glowed about them, and they saw that the professor had switched on his miniature search lamp. They remembered how he had told them to work the apparatus, and soon tiny gleams shot out from their helmets.

The professor pointed ahead, for not a sound could be heard, and the boys followed him.

It was a new sensation, this walking along the bed of the ocean. At first the great pressure of water, even though the steel lined diving suits kept most of it off, was unpleasant. Gradually, however, the boys became used to it. They had to move slowly, for the water was denser than the air and impeded their progress.

In a few minutes they reached the forward end of the _Porpoise_. Now they were to solve the mystery of what had stopped the submarine. For a few moments they could distinguish nothing.

Suddenly the boys felt the professor grasping their arms. They looked in the direction he pointed. There in the diffused glare from the search light and the illumination of their helmet lamps they saw, wrapped about the forward shaft opening a gigantic squid or devil fish. Its soft, jelly-like body completely covered the opening of the shaft preventing any water from entering, and thus stopping any forward motion to the ship.

This was what had caused all the trouble. The _Porpoise_ had run into the monster, who feeling what it must have thought an enemy, had grasped the submarine with its long sinuous arms.

The professor hesitated a moment. Then he slowly raised his electrical gun, and took aim at the hideous ma.s.s. The boys followed his example. At Mr. Henderson's signal they all fired together.

From the muzzles of the guns darted small barbs that carried with them a strong shock of electricity, from storage batteries in the shoulder pieces of the weapons. Three of them were enough to produce death in an animal as large as a whale.

The devil fish quivered. Then the water about it suddenly grew black, and the boys and the professor were in dense darkness, for the squid had dyed the ocean with a dark liquid from the sack it carried for the purpose.

The explorers groped their way to the left, having fortunately grasped hands after firing their guns, to prevent being separated in case the terrible fish began a death struggle.

Luckily Professor Henderson went in the right direction and managed to locate the _Porpoise_. Then, feeling along her steel sides, he led the boys through the inky blackness to the water chamber by which entrance could be had to the interior.

In a few minutes all three were safely inside and had removed their diving suits. The others crowded about, anxious to learn what had happened. The inventor related it briefly.

Once more the engines were started. This time there was no hanging back on the part of the _Porpoise_. The big screw revolved, the water came in the shaft and was thrust out of the rear end, making a current that sent the craft ahead swiftly. The gigantic fish had been killed, and its body no longer obstructed progress.

"Now we'll rise to the surface and see how it feels to sail along that way for a while," said the professor as he started the pumps that emptied the tanks. In a little while the ship was floating on the waves.

It was now night, and the clouds overhead made it so dark that it was hard to see ten feet in advance. The professor did not want to use the searchlight for he did not care to have his presence discovered by curious persons. So he ran the ship at half speed.

"Where are we now?" asked Mark, who had entered the conning tower, where the professor was steering.

"Somewhere's off the coast of South Carolina," replied the inventor.

The next instant there was a sudden shock and jar. The ship quivered from stem to stern, and came to an abrupt stop.

"We've hit something!" exclaimed the professor, shutting down the engines with a jerk of the lever.

CHAPTER IX

A PRICE ON THEIR HEADS

On board the _Porpoise_ there was great excitement. Washington, with Andy, Tom, Bill and Jack came running from the engine room.

"What is it?" cried Jack.

"I don't know," answered the professor as calmly as he could. "We'll soon see, however."

He switched on the searchlight and peered from the conning tower.

"Can you see anything?" asked Andy, anxiously.

"I can," announced the inventor.

"What?"

"Land," replied Mr. Henderson. "We've hit the coast."

"I hope we ain't done no damage," put in Washington.

"Do you mean to the coast or to us?" asked the professor, with a smile.

"I guess there isn't much danger in ramming the sh.o.r.e excepting to the _Porpoise_. However, we do not seem to be in any immediate trouble."

He tested various wheels and levers, and announced that, aside from the jar, which might have started some of the machinery, the _Porpoise_ was unharmed.

The cover of the man-hole was loosened and, one after another, the adventurers crawled out on the small deck or platform. It took them a little while to become accustomed to the darkness, but soon they were able to make out that they had run on the muddy bank of the ocean beach.

The tide was low and the _Porpoise_ had rammed her nose well into the soft muck, which accounted for the lack of damage.

"Well, I guess there is nothing to do excepting to wait for morning,"

said Mr. Henderson. "It doesn't look like a very lively neighborhood about here. I don't believe we'll be disturbed."

Save for the splash and lapping of the waves and the sound of the wind, it was as quiet as the proverbial graveyard. Not a light showed on sh.o.r.e, and the gleam from the search lamp of the _Porpoise_ cut the darkness like a small moonbeam.

"If there's nothing to do I'm going to turn in," said Andy. "I'm tired."

The professor said this was a good suggestion, and, leaving instructions that Washington and Bill were to divide the night's watch between them, the inventor sought his bunk.

The boys remained on deck a few minutes longer.

"We certainly are getting our share of adventures," remarked Jack.

"I should say so," answered Mark.

"Gollyation yes!" exclaimed Washington. "You-uns done most been eat by dat air koslostrous specimen ob a parralleledon! I'm glad I didn't go.

But I'se brave enough!"

"What's that?" asked Mark suddenly, pointing to an object floating on the water.

Washington turned to behold something white drifting along.

"Oh my good land ob mercy! It's a ghost!" the colored man yelled. "It's a ghost! Land a' ma.s.sy! Hide me some where, quick!"