Then, when Koku saw the man aim at the big searchlight the giant sprang at him, and there was a scuffle.  The gun went off, and the man escaped.  An examination of the weapon he had left behind showed that it carried a highly explosive shell, which, had it hit the lantern, would have completely destroyed it, and might have damaged the airship.

“It was the smugglers, without a doubt,” declared Mr. Whitford.  “You can’t get away from this place any too soon, Tom.  Get a new hiding spot, and I will communicate with you there.”

“But they are on the watch,” objected Ned.  “They’ll see where we go, and follow us.  The next time they may succeed in smashing the lantern.”

“And if they do,” spoke Tom, “it will be all up with trying to detect the smugglers, for it would take me quite a while to make another searchlight.  But I have a plan.”

“What is it?” asked the government agent.

“I’ll make a flight to-day,” went on the young inventor, “and sail over quite an area.  I’ll pick out a good place to land, and we’ll make our camp there instead of here.  Then I’ll come back to this spot, and after dark I’ll go up, without a light showing.  There’s no moon to-night, and they’ll have pretty good eyes if they can follow me, unless they get a searchlight, and they won’t do that for fear of giving themselves away.

We’ll sail off in the darkness, go to the spot we have previously picked out, and drop down to it.  There we can hide and I don’t believe they can trace us.”

“But how can you find in the darkness, the spot you pick out in daylight?” Mr. Whitford wanted to know.

“I’ll arrange same electric lights, in a certain formation in trees around the landing place,” said Tom.  “I’ll fix them with a clockwork switch, that will illuminate them at a certain hour, and they’ll run by a storage battery.  In that way I’ll have my landing place all marked out, and, as it can only be seen from above, if any of the smugglers are on the ground, they won’t notice the incandescents.”

“But if they are in their airship they will,” said Mr. Damon.

“Of course that’s possible,” admitted Tom, “but, even if they see the lights I don’t believe they will know what they mean.  And, another thing, I don’t imagine they’ll come around here in their airship when they know that we’re in the neighborhood, and when the spy who endeavored to damage my lantern reports that he didn’t succeed.  They’ll know that we are likely to be after them any minute.”

“That’s so,” agreed Ned.  “I guess that’s a good plan.”

It was one they adopted, and, soon after Mr. Whitford’s visit the airship arose, with him on board, and Tom sent her about in great circles and sweeps, now on high and again, barely skimming over the treetops.  During this time a lookout was kept for any other aircraft, but none was seen.

“If they are spying on us, which is probably the case,” said Tom, “they will wonder what we’re up to.  I’ll keep ’em guessing.  I think I’ll fly low over Mr. Foger’s house, and see if Andy has his airship there.  We’ll give him a salute.”