With her company silent as graven images at the sheer wonder of it, the submarine continued her plunge into the depths. Up in the conning-tower Lockyer clutched a hand-rail, holding on till his nails dug into his flesh. Every sense within him was singing an anthem of praise. His diving torpedo boat was, indeed, proving herself worthy of the confidence he had placed in her.

“Better set her on an even keel now!” he reminded Lieutenant Parry, presently.

Till that moment the officer had forgotten everything but the wonderful fact that the boat was diving—diving as if she had never been used to anything else.

Instantly the officer set the needful machinery in motion, and silently the after tanks began to fill. The water was sucked in through the sea-valves, with hardly a sound, now that they were running where the pressure of the water was more intense. Fifty feet now showed upon the gauge. Lieutenant Parry scanned the chart in front of him, illuminated by a hooded light.

“We’ve got plenty of sea room under our keel,” he said; “the chart gives us 400 fathoms here. Lockyer, I’m glad, old man, for your sake, and for the sake of somebody else.”

“Thanks,” said Lockyer simply, and though they could not see his face, they knew that it softened as he thought of the girl who had christened his diving boat.

“Here, boys, come up in the conning-tower,” ordered the naval officer presently, “Mr. Stark and I want to take a look about below.”

So it came about that, presently, Ned had the wheel once more in his hands. “What’s the course, sir?” he inquired, as the officer relinquished the spokes.

“Two points north of west,” was the response; “keep her on it till further orders.”

Ned saluted, and the officer went below, leaving the young steersman, Herc, Tom Marlin, and Sim in the conning-tower.

It was an eerie, strange feeling, this, of steering such a craft through the inky expanse spread about. Viewed through the lenses of the tower, the blackness seemed almost solid. Through the inky depths the submarine, a blind, swift-moving monster, nosed her way. Not so swift-moving now though, for her speed had been slowed down to a bare ten miles.

“Well?” asked Ned, as the officers vanished in the wake of the inventor for an inspection of the engine room.

“Well?” sighed Herc, “how about you?”

“It’s great,” cried Ned enthusiastically; “I tell you though, it gives a fellow a funny feeling, steering right ahead into the darkness. Seems as if you were butting into something solid all the time.”

“W-w-w-what would happen if we ran into a water-logged hull?” asked little Sim, with a bit of a quaver in his voice.

“Or hit a weak-fish?” chuckled Herc.

“I tell you, lads,” put in old Tom solemnly, “if we ever hit a wreck goin’ at this clip, it would be either the wreck, or us. With chances in favor of the wreck.”

“Reckon that’s so,” rejoined Ned, with a bit of a nervous catch in his voice; “we’d crumple up like a busted egg-shell.”

“Not much doubt of that, lad,” agreed the old tar, in a sepulchral voice.

“Oh say, you fellows ought to have been undertakers,” exclaimed Herc, impatiently; “for my part,—rattlesnakes and rickshaws! I’m going to enjoy the ride and not worry about what might happen.”

“That’s right,” heartily rejoined Ned; “it’s no use worrying about what might happen. Suppose Dewey had worried about that at Manila. If you want to do any supposing, just suppose that we are creeping along now up under a hostile battleship. Presently, we will be ordered forward into the torpedo-room, and at the word of command we’ll launch one of our Whiteheads. We wouldn’t hear a sound, but as we sneaked off we’d know that we’d justified our existence. Done what we were built for.”

“Suppose we change the subject,” suggested the red-headed lad; “let’s talk about the farm. Wouldn’t old gran’pa be scared if we had him down here?”

“Not any more so than he was that time he fell into the well, I imagine,” laughed Ned. “Isn’t it wonderful, though, old fellow, to think that not more than a year ago we were doing fall plowing, and now here we are, down fifty—no fifty-two feet—under the waves——”

“And plowing along still,” grinned Herc, “but we’ve got 3,000 horse-power behind us now instead of being hitched on to that spavined old mare and the green, wall-eyed colt.”

Down below, the officers and Mr. Lockyer were here, there and everywhere; testing, tapping, trying. But there did not seem to be a hitch. Every joint was as tight as a drum under the terrific pressure now exerted on the steel sides, and, except for the “sweating” of the steel, the boat was as dry as a bone.

Stepping to the compressed-air gauges, the inventor scanned them carefully. One of them showed a slight decrease in pressure. Once more the electric radiators were put into action, expanding the air at once.

“How’s the engine?” asked Lieutenant Parry, pausing by Andy Bowler, as he bent above the shining, moving bits of mechanism, each sliding and flashing in and out at its own appointed time.

“Running sweet as a baby’s sleep, sir,” was the whimsical response; “we’ve got her well doused with oil, and there’s not a bearing that’s even warm.”

“Pretty good for a new engine, eh, Mr. Parry?” smiled Channing Lockyer.

“It is, indeed, sir,” was the response; “I must say, that from what I have seen, that your compressed-air engine has an electric one beaten fifteen ways for submarine use.”

“Well, there’s only one thing left to complete this part of the programme,” said the lieutenant, as they sank down on the comfortable leather-upholstered seats in the cabin.

“And that is?” asked Midshipman Stark.

“To rise again, to be sure,” struck in the inventor.

Up in the conning-tower the boys could hear the conversation below distinctly.

“Hammocks and humming birds!” gasped Herc, “blessed if I hadn’t quite forgotten about the rising part of it.”

“It’s quite important, though,” said Ned, with a dry smile.

“Above there!” came a sudden hail from below in Lieutenant Parry’s voice.

“Aye, aye, sir!” bawled back Ned.

“Do you understand how to work the air-changing device?”

“Aye, aye, sir.”

“Then set it in motion, please. We wish to test how quickly we can get a fresh supply.”

Ned reached above his head, and turned a valve, which, by an ingeniously simple arrangement, opened the exhaust valve by which the bad air was driven out and admitted a fresh supply at the same time.

“I did begin to notice the air getting a little stale,” commented Herc; as he did so, “Ah-h-h-h-h!” he exclaimed the next instant, throwing out his chest and inflating his lungs with the fresh air which, as if by magic, flooded the place, “that’s as good as a sea breeze.”

And so they all agreed. The air had been getting fouler than they had really noticed in their intense concentration on the running of the boat.

“Well,” said the lieutenant below, “there’s no doubt about that device working as well as everything else about the Lockyer. And now let us see about getting to the surface. We must, according to my calculations, be not far off the light by this time.”

“Very well, then,” said Mr. Lockyer, with a confident smile. “It’s ho! for the surface. And here, gentlemen,” he said, producing a long, shiny bit of metal with a slot on one end, “is the means by which we are to get there.”

So saying, he stepped to the side of the cabin where, against the wall, appeared the top of a valve. Fitting the slot of the wrench over this projection, he gave a gentle twist. Instantly a swishing sound followed, not unlike the loud screaming hiss of escaping steam from the safety valve of a locomotive.

“The biggest air pumps we have are now at work driving out the water from all the tanks simultaneously,” he explained; “the water is being expelled at the rate of hundreds of gallons a minute.”

“Queer we don’t feel that we are rising,” commented the naval officer; “the balance in this boat seems to be better preserved than in the present type. She does not tip or tilt at all on her upward way.”

“Yet we are rising,” said the inventor. He pointed to the depth indicator.

Its hand was rising rapidly. First, it showed thirty, then twenty, then ten, and then five feet.

“We’re awash, sir,” came a surprised hail from the conning-tower the next instant.

“Of course we are,” cried Channing Lockyer delightedly. “I didn’t tell you boys we were going to rise, because I wished to try to take you by surprise. I see I have succeeded in doing so.”

“You certainly have,” rejoined Ned; “why, I couldn’t even feel any noticeable shifting of the course.”

“Now, gentlemen, come on deck and see the stars,” smiled Channing Lockyer, leading the way up the steel ladder. In a jiffy he had the cover of the conning-tower opened, and out they stepped upon the wet decks. A gentle swell was running, upon which the slowly moving submarine rose and fell evenly.

“Why this is the very poetry of motion!” cried Lieutenant Parry delightedly.

Above the party shone the steady stars, brightly reflected on the heaving expanse of waters, as if they would twinkle a welcome to this visitor from old Neptune’s realm. For a few seconds the sheer exultation of it filled them to the exclusion of all else. Then Mr. Lockyer, poking his head over the conning-tower top, ordered some more speed.

Obediently the little diver forged ahead, her swifter motion now sending the spray flying back over her decks—or, rather, back. But not one of the absorbed party on the surface minded that. Clinging to the handrails round the edge of the tower, they were enjoying every minute of it, when there came a sudden hail from the naval officer.

“What’s that dead ahead there? It looks like a schooner’s sails blotting out the stars.”

“I see it,” rejoined the inventor, “it is a vessel of some sort.”

“And without lights,” said Midshipman Stark; “as naval officers we ought to give them a warning, sir.”

“What do you say, Lockyer?” asked the officer; “shall we overhaul them and give them a surprise?”

“By all means,” was the answer; “this craft was built for duty on the high seas, you know.”

“Hand me out the night glasses, Strong, will you,” said the inventor; “there’s a strange sail ahead.”

“It’s a schooner, all right, and a fast one, too,” said Mr. Lockyer the next instant. Lieutenant Parry and the midshipman soon confirmed this judgment. A great spire of dark canvas was now visible against the night.

“Better bear up on her, Strong,” ordered the naval officer; “schooners without lights in these waters are a menace to navigation.”

Ned could see the dim outline of this strange craft through the lenses, and at once spun his wheel over and headed for the dark boat.

“Schooner, ahoy!” shouted Lieutenant Parry, as they came within hailing distance; “where are your lights?”

There was no answer, and the swish of the water under her forefoot, and the creak of the straining rigging, as the sailing craft forged along, were the only sounds that broke the stillness.

“Ahoy there, schooner!” came another hail. Then in a sharper voice. “Lie to, there.”

For all the rejoinder that came back the schooner might as well have been a ghostly craft manned by phantoms. Only the occasional creak of a block came from her.

“Lay alongside of her, Strong,” ordered the officer, in a sharp voice; “it begins to look as if there really were something wrong aboard her.”

Ned obeyed instructions, and soon there was not more than ten feet of water between the sailing craft and the submarine.

“Try them again, sir,” suggested Mr. Stark.

“Confound them,” grunted the officer; “they must be a crew of deaf mutes.”

He placed his hands to his mouth funnel-wise and gave another sharp hail.

“Ahoy there, schooner, we want to speak to you.”

The answer was as startling as it was unexpected. A sudden red flare cut through the night. Then came the whistle of a bullet, followed by a sharp report.

“Take that, curse you!” came from a man whose head showed for an instant above the schooner’s stern rail.