"Do you think they know we are here, Tom?" asked Mr. Whitford, as he stood at the side of the young inventor in the motor room.

"I don't believe so, as yet. They can't hear us, and, unless they have pretty powerful gla.s.ses, they can't pick us up. We can soon tell however, if they are aware that we are following them."

"Have you made any plan about capturing them?"

"No, I'm going to wait and see what turns up. I can't certainly chase two of them, if they separate, and that's why I'm going to cripple one if I have to."

"But won't that be dangerous? I don't want to see any of them killed, or even hurt, though they are smugglers."

"And I don't want to hurt them, either. If worst comes to worst I'm going to put a few holes in the wing planes of the smaller craft.

That will cause her to lose headway, and she can't keep up. They'll have to volplane to earth, but, if they know anything at all about airships, they can do that easily, and not get a bit hurt. That will put them out of the race, and I can keep on after the big ship. I fancy that carries the more valuable cargo."

"I presume so. Well, don't bring the one to earth until you get over Uncle Sam's territory, and then maybe there will be a chance to capture them, and the goods too."

"I will," promised Tom. They were still over Canadian territory, but were rapidly approaching the border.

"I think I will send a wireless to my men in Logansville, to start out and try to pick up the crippled airship after you disable her,"

decided Mr. Whitford, and as Tom agreed that this was a good plan, the wireless was soon cracking away, the government agent being an adept in its use.

"I've told them we'd give another signal to tell them, as nearly as possible where we made them take to earth," he said to Tom, and the young inventor nodded in agreement.

"Ned in them ship?" asked Koku, as he came back from the pilot house to report that Mr. Damon was all right, and needed no help.

"Yes, I think Ned is in one of them," said Tom. "The big one most likely. Poor Ned a prisoner! Well, I'll soon have him away from them--if nothing happens," and Tom looked about the motor room, to make sure that every piece of apparatus was working perfectly.

The two airships of the smugglers were hanging close together, and it was evident that the larger one had to make her pace slow, so as not to get ahead of the small craft. Tom followed on relentlessly, not using half his speed, but creeping on silently in the darkness.

"We're over the United States now," said Mr. Whitford, after a glance earthward through the binoculars. "Let 'em get a little farther over the line before you pop 'em with your electric rifle, Tom."

Our hero nodded, and looked out of a side window to note the progress of the smugglers. For several miles the chase was thus kept up, and then, suddenly the smaller craft was seen to swerve to one side.

"They are separating!" cried Mr. Whitford, at the same time Mr.

Damon called through the tube from the pilot house:

"Which one shall I follow, Tom?"

"The big one," the youth answered. "I'll take care of the other!"

With a quick motion he flashed the current into the great searchlight, and, calling to Mr. Whitford to hold it so that the beams played on the small aeroplane, Tom leveled his wonderful electric rifle at the big stretch of canvas. He pressed the lever, a streak of blue flame shot out through an opened port, and, an instant later, the small craft of the smugglers was seen to stagger about, dipping to one side.

"There they come!" cried Mr. Whitford. "They're done for!"

"One shot more," said Tom grimly. "It won't hurt 'em!"

Again the deadly electric rifle sent out its wireless charge, and the airship slowly fluttered toward the earth.

"They're volplaning down!" cried Tom. "That's the end of them. Now to catch the other!"

"Take the lantern!" cried Mr. Whitford. "I'm going to send a wireless to my men to get after this disabled craft."

Tom swung the beam of the searchlight forward and a moment later had picked up the big aeroplane. It was some distance in advance, and going like the wind. He heard the automatic camera clicking away.

"They speeded her up as soon as they saw what was on!" cried Tom.

"But we haven't begun to go yet!"

He signalled to Mr. Damon, who pulled over the accelerating lever and instantly the Falcon responded. Now indeed the race was on in earnest. The smugglers must have understood this, for they tried all their tactics to throw the pursuing airship off the track. They dodged and twisted, now going up, and now going down, and even trying to turn back, but Tom headed them off. Ever the great beam of light shone relentlessly on them, like some avenging eye. They could not escape.

"Are we gaining?" cried Mr. Whitford.

"A little, and slowly," answered Tom. "They have a bigger load on than when we chased them before, but still they have a speed almost equal to ours. They must have a magnificent motor."

Faster and faster sped on the Falcon. The other craft kept ahead of her, however, though Tom could see that, inch by inch, he was overhauling her.

"Where do they seem to be heading for?" asked the government agent.

"Shopton, as near as I can make out," replied the youth. "They probably want to get there ahead of us, and hide the goods. I must prevent that. Mr. Damon is steering better than he ever did before."

Tom shifted the light to keep track of the smugglers, who had dipped downward on a steep slant. Then they shot upward, but the Falcon was after them.

The hours of the night pa.s.sed. The chase was kept up. Try as the smugglers did, they could not shake Tom off. Nearer and nearer he crept. There was the gray dawn of morning in the sky, and Tom knew, from the great speed they had traveled that they must be near Shopton.

"They're slowing up. Tom!" suddenly cried Mr. Whitford who was watching them through an open port.

"Yes, I guess they must have heated some of their bearings. Well, here's where I capture them, if it's ever to be. Koku, let down the grappling anchor."

"Are you really going to capture them, Tom?" asked the custom officer.

"I'm going to try," was the answer, as Koku came back to say that the anchor was dragging over the stern by a long rope.

"You work the light, Mr. Whitford," cried Tom. "I'm going to relieve Mr. Damon in the pilot house. He can help you here. It will be all over in another minute."

In the pilot house Tom grasped the steering levers. Then in a final burst of speed he sent his craft above, and past that of the smugglers.

Suddenly he felt a shock. It was the grappling anchor catching in the rail of the other air craft. A shout of dismay arose from the smugglers.

"You've got 'em! You've got 'em, Tom!" yelled Mr. Whitford.

"Bless my hasty pudding! So he has!" gasped Mr. Damon.

Changing the course of his craft Tom sent the Falcon toward the earth, pulling the other aeroplane with him. Down and down he went, and the frantic efforts of the smugglers to release themselves were useless. They were pulled along by the powerful airship of our hero.

A few minutes later Tom picked out a good landing place in the dim light of the breaking dawn, and went to earth. Jamming on the brakes he leaped from the pilot house to the stern of his own craft, catching up his electric rifle. The other airship, caught by the grappling anchor at the end of a long rope, was just settling down, those in her having the good sense to shut off their power, and volplane when they found that they could not escape.

As the smugglers' craft touched the earth, several figures leaped from her, and started to run away.

"Hold on!" cried Tom. "I've got you all covered with the electric rifle! Don't move! Koku, you, and Mr. Whitford and Mr. Damon take care of them. Tie 'em up."

"Bless my hat band!" cried the eccentric man. "What a great capture!