"Have you given up all suspicion of the Fogers?" asked the young inventor.

"Yes. But I still think Shopton is somehow involved in the custom violations. I'm going to put one of my best men on the ground here, and go to the border myself."

"Well, I'll be ready to start in a few days," said Tom, as the government agent departed.

For the next week our hero and his chum were busy completing work on the great searchlight, and in attaching it to the airship. Koku helped them, but little of the plans, or of the use to which the big lantern was to be put, were made known to him, for Koku liked to talk, and Tom did not want his project to become known.

"Well, we'll give her a trial to-night," said Tom one afternoon, following a day of hard work. "We'll go up, and flash the light down."

"Who's going?"

"Just us two. You can manage the ship, and I'll look after the light."

So it was arranged, and after supper Tom and his chum, having told Mr. Swift were they were going, slipped out to the airship shed, and soon were ready to make an ascent. The big lantern was fastened to a shaft that extended above the main cabin. The shaft was hollow and through it came the wires that carried the current. Tom, from the cabin below, could move the lantern in any direction, and focus it on any spot he pleased. By means of a toggle joint, combined with what are known as "lazy-tongs," the lantern could be projected over the side of the aircraft and be made to gleam on the earth, directly below the ship.

For his new enterprise Tom used the Falcon in which he had gone to Siberia after the platinum. The new noiseless motor had been installed in this craft.

"All ready, Ned?" asked Tom after an inspection of the searchlight.

"All ready, as far as I'm concerned, Tom."

"Then let her go!"

Like a bird of the night, the great aeroplane shot into the air, and, with scarcely a sound that could be heard ten feet away, she moved forward at great speed.

"What are you going to do first?" asked Ned.

"Fly around a bit, and then come back over my house. I'm going to try the lantern on that first, and see what I can make out from a couple of miles up in the air."

Up and up went the Falcon, silently and powerfully, until the barograph registered nearly fourteen thousand feet.

"This is high enough." spoke Tom.

He shifted a lever that brought the searchlight into focus on Shopton, which lay below them. Then, turning on the current, a powerful beam of light gleamed out amid the blackness.

"Jove! That's great!" cried Ned. "It's like a shaft of daylight!"

"That's what I intended it to be!" cried Tom in delight.

With another shifting of the lever he brought the light around so that it began to pick up different buildings in the town.

"There's the church!" cried Ned. "It's as plain as day, in that gleam."

"And there's the railroad depot," added Tom.

"And Andy Foger's house!"

"Yes, and there's my house!" exclaimed Tom a moment later, as the beam rested on his residence and shops. "Say, it's plainer than I thought it would be. Hold me here a minute, Ned."

Ned shut off the power from the propellers, and the airship was stationary. Tom took a pair of binoculars, and looked through them at his home in the focus of light.

"I can count the bricks in the chimney!" he cried in eagerness at the success of his great searchlight. "It's even better than I thought it was! Let's go down, Ned."

Slowly the airship sank. Tom played his light all about, picking up building after building, and one familiar spot after another.

Finally he brought the beam on his own residence again, when not far above it.

Suddenly there arose a weird cry. Tom and Ned knew at once that it was Eradicate.

"A comet! A comet!" yelled the colored man. "De end ob de world am comin'! Run, chillens, run! Beware ob de comet!"

"Eradicate's afraid!" cried Tom with a laugh.

"Oh good mistah comet! Doan't take me!" went on the colored man. "I ain't neber done nuffin', an' mah mule Boomerang ain't needer. But ef yo' has t' take somebody, take Boomerang!"

"Keep quiet, Rad! It's all right!" cried Tom. But the colored man continued to shout in fear.

Then, as the two boys looked on, and as the airship came nearer to the earth, Ned, who was looking down amid the great illumination, called to Tom:

"Look at Koku!"

Tom glanced over, and saw his giant servant, with fear depicted on his face, running away as fast as he could. Evidently Eradicate's warning had frightened him.

"Say, he can run!" cried Ned. "Look at him leg it!"

"Yes, and he may run away, never to come back," exclaimed Tom. "I don't want to lose him, he's too valuable. I know what happened once when he got frightened. He was away for a week before I could locate him, and he hid in the swamp. I'm not going to have that happen again."

"What are you going to do?"

"I'm going to chase after him in the airship. It will be a good test for chasing the smugglers. Put me after him, Ned, and I'll play the searchlight on him so we can't lose him!"

CHAPTER X

OFF FOR THE BORDER

"There he goes, Tom!"

"Yes, I see him!"

"Look at him run!"

"No wonder. Consider his long legs, Ned. Put on a little more speed, and keep a little lower down. It's clear of trees right here."

"There he goes into that clump of bushes."