S-w-ish-ish-ish! The roar of the water, as the powerful pumps sucked it into the submerging tanks, filled the interior of the Barr submarine.

Suddenly she gave a forward plunge, and the boys now learned for what purpose several handholds were attached to the cabin walls!

"Say, this is a queer sensation, isn't it?" gasped Merritt, looking rather alarmed as the downward rush could be distinctly felt. In the engine room the electric motors had been connected, and in the conning tower the hatch which gave entrance and egress when on the surface had been clamped tightly down.

"S-s-pose we don't come up again?" exclaimed Donald.

"We haven't got an awful lot to eat on board," murmured Tubby anxiously.

"Gracious, how far down are we going?" spoke Merritt, as five minutes pa.s.sed and still the _Peacemaker_ continued her descent into the depths of the sea.

All at once the tilting motion ceased, the _Peacemaker's_ stern tanks were filled, and she floated on an even keel. Leaving the care of the wheel to Ensign Hargreaves, who, as we know, was familiar with the usual type of submarine, Mr. Barr came into the cabin.

"Well, boys, what do you think of it?" he asked with a smile.

"It's g-g-great," rejoined Tubby, with a notable lack of his usual a.s.surance.

"And now I suppose you'd like to see what the bottom of the sea looks like. We are down some two hundred fathoms and about fifty miles off the coast. Should you care to see how things look down here?"

"How will that be possible?" asked Merritt.

By way of reply Mr. Barr went to the starboard wall of the cabin and pulled a lever connecting with a worm gear. As he did so, a great section of the _Peacemaker's_ steel side drew back and revealed a plate gla.s.s window set between the inner and outer "skins" of the craft.

The boys crowded round the window and peered out eagerly. But to their disappointment they could see no more of their surroundings than if they had been looking out of a train window on a dark night. It was as black as a wolfs mouth at those unknown depths.

"Why, we can't see anything," came a disgruntled chorus.

"Wait a minute," smiled the inventor.

[Ill.u.s.tration: THE BOYS CROWDED ROUND THE WINDOW AND PEERED OUT EAGERLY.]

Pressing a b.u.t.ton, he extinguished the cabin lights. Then he opened a sort of closet in the wall alongside the window and swung out a powerful, though small, searchlight attached to an adaptable arm in the same manner as a desk telephone.

There was a clicking sound, and a flood of white light pierced the blackness outside. The boys broke into delighted exclamations as the powerful rays revealed all sorts of fish, many of odd shapes and colors, attracted by the light.

Suddenly a dark, shadowy form swung into view. Instantly the other fish vanished, and the boys saw that the newcomer was a large shark swimming leisurely along.

No doubt he wondered who the strangers in his deep sea abode could be, for he swam up close to the window, causing the boys to shrink back.

They quite forgot that between them and the tiger of the deep was a solid plate of gla.s.s as strong almost as steel.

The shark gazed at the window for an instant and then vanished. With its disappearance, the other fish reappeared and kept the submarine company, for all the world like sea gulls circling round a ship entering port.

"I wonder if they are hungry and want us to throw some food out to them," said Tubby stolidly, as he gazed at the finny tribes darting here and there in the searchlight's rays.

"Gracious, do you think that the fish have the same appet.i.te as you have?" laughed Merritt.

"Just the same, some of those fellows would taste all right broiled,"

declared the stout youth, at which there was a general laugh.

After an hour spent in this manner the searchlight was switched off and the panels slid back into place.

"I think we will rise now," said the inventor; "you boys had better hold on, for we may go up pretty quick."

"I hope we _do_ go up," muttered Tubby, rather nervously. The stout youth was not particularly in love with the dark depths in which they were navigating. In fact, all the lads, though they did not admit it, experienced a longing for daylight. It was an awe-inspiring feeling--too awe-inspiring to be comfortable--to be in the depths of the ocean where no keel had ever before plowed.

Mr. Barr remounted to the conning tower. A minute later a renewal of the swishing sound told that the pumps were emptying the tanks at the rate of a thousand gallons a minute. The submarine could be felt to leap upward toward the surface. The boys held on for dear life, exchanging rather alarmed glances.

All at once the pace slackened, and the swishing sound ceased. Mr. Barr had decided that the pace was too swift and had cut off the pumps.

"Well, thank goodness that's over!" gasped Donald. "At the rate we were going up we'd have bounced clean out of the sea."

"I guess we're all right now," remarked Merritt.

The words had hardly left his lips when there came a jar and a b.u.mp that shook the submarine in her every frame and rivet.

The boys were thrown from their feet and hurled about the cabin. At the same instant the engines stopped and the submarine began to back, but slowly, like a stricken animal.

"We've rammed something!"

"We're sinking!"

These and a hundred other exclamations came from the alarmed boys.

Mr. Barr poked his head down into the cabin.

"Are you all right below?" he asked.

"Yes; but what has happened?"

"Have we been badly damaged?"

"Are we sinking?"

The above questions were all shouted at once in the tense excitement.

Barton, his face white as ashes, came out of his engine room.

"What did we hit?" he demanded in a frightened voice.

"I don't know; but we struck something, possibly a sunken wreck, a hard blow," was the inventor's reply. Although his face was deadly pale, his voice was without a tremor as he spoke.

"We must make an examination at once," he went on. "Andrews, Higgins, and Ross," addressing the three sailors who had appeared from forward, "make an examination forward at once and see if any of the plates have started. If you find a suspicion of a leak report to me at once."

The sailors, trained in naval discipline, saluted, and hastened off on their errand.

"If we are leaking, what are we to do?" demanded Rob.

"Meet death as bravely as we can," was the reply in steady tones; "submarines carry no boats and we must go to the bottom unless we can find some way to stop the leak."