But Dooley, for he it was, said sharply:

“No! You mustn’t kill one of them. I want them held for prisoners. I have a purpose in view!”

“All right!” said Bowler, sullenly.

Toward the cabin door the interlopers crept. In a jiffy they had taken possession of every part of the air-ship.

A terrible peril hung over the heads of our sleeping voyagers, and yet they slept on, all unsuspecting it.

Frank Reade, Jr., was awakened from his slumbers by a savage clutch at the throat. Strong hands forced him down and bound him.

The captain made a terrific resistance but was overpowered. Barney was also served the same.

The aerial voyagers were thus all made prisoners in a twinkling. It was a sudden turning of tables.

The jubilation of Dooley can hardly be described in words.

That the villain’s plans should have succeeded so well was remarkable.

He glowered at Frank Reade, Jr., saying:

“Well, now, ye can afford to be a little more civil with me, can’t ye? Oh, I tell ye, Jerry Dooley is a hard man to beat!”

“You are a treacherous dog,” said Frank, angrily, “after making a truce, to treat us thus.”

“All is fair in war,” quoted the wretch. “You are lucky to have been spared your lives.”

“What do you expect to gain by this trick? We have none of the gold.”

“What have we not gained?” exclaimed the villain, exultantly. “Only think—the wonderful air-ship is ours, to become freebooters of the skies if we choose, and the inventor is our hostage.”

Frank smiled grimly.

“So you intend to make use of the air-ship?” he asked.

“Why not?”

“You will find it not an easy machine to manage, I think.”

“Ah, but that is why I spared your life. You shall manage it for us.”

“Indeed!” said Frank with anger. “You have reckoned without a host. I shall do nothing of the kind.”

An ugly light shone in Dooley’s eyes.

“You won’t, eh?”

“Never!”

“Well, we shall see. You may be induced to change your mind. Make no rash announcements!”

“Oh, for a moment of liberty,” muttered Frank, gnashing his teeth. “I would pluck that rascal’s wings for him.”

“I wish you had it, Frank,” said Nicodemus; “is there no way we can turn the tables upon them?”

“We can only wait and hope,” said Frank.

Barney was raving and raging furiously.

“It’s the stupid work of that naygur,” he cried angrily. “Shure av they’ve finished him it’s small loss, afther givin’ us roight inter the hands av the inemy, bad cess to him!”

Meanwhile the gold seekers had overrun the air-ship.

There was no part of it to which they did not penetrate. Everything on board was subject to scrutiny.

No move was made, however, to change the position of the air-ship until daylight came.

Then Dooley and several of his companions undertook to make an examination of the electrical machinery.

It probably occurred to them that they might fathom its construction and learn to operate the air-ship themselves.

But they were bewildered with all its intricacies and were speedily obliged to abandon that idea. They finally went into the pilot-house and began trifling with the keyboard.

And right here they made a mistake. For by an inadvertence Bowler pressed the helice lever wide open.

What happened was a literal surprise to all.

There was a terrific, whirring sound, and up into the air shot the air-ship. Bowler did not know how to press the lever back and could not therefore check the craft’s ascent.

Both he and Dooley rushed out on deck.

They stared down at the rapidly receding earth, half in fright. As it happened none of the other gold-seekers were aboard.

Dooley was angry.

“What the deuce did you do that for, Bowler?” he cried. “Now undo your work lively.”

“I can’t do it, sor!” replied the sailor, as he tried in vain to reverse the lever. It would not work.

“There is a way to do it,” cried Dooley, angrily. “Confound you for a blockhead! We shall soon get to heaven at this rate. Let me see it, you ass!”

But Dooley had no better luck! Still upward raced the air-ship. The two rascals were in a state of terror.

Cold perspiration oozed from their pores and they trembled as if with the ague.

“I didn’t mean to do it, skipper,” declared Bowler, aghast; “it was an accident. Won’t we ever get back to the earth?”

“Not at this rate,” huskily declared the senior villain.

And now an alarming state of affairs ensued. The air grew so rare that their eyeballs began to ache and cold chills seized them.

“Great Jericho!” gasped Dooley. “I can’t stand this. I’ve heard it said that when you get a certain number of miles up in the air you can find no air to breathe and you must stifle.”

“Great lobster pots!” wailed the terrified Bowler; “stop the thing some way.”

“I can’t,” said............