“It’s from Mr. Whitford!” he exclaimed, when he had written it down, and had sent back an answer, “He says:  ’Have a tip that smugglers will try to get goods over the border at some point near Niagara Falls to-morrow night.  Can you go there, and cruise about?  Better keep toward Lake Ontario also.  I will be with you.  Answer.’”

“What answer did you send?” asked Ned.

“I told him we’d be on the job.  It’s quite a little run to make, and we can’t start until after dark, or otherwise some of the smugglers around here may see us, and tip off their confederates.  But I guess we can make the distance all right.”

Mr. Whitford arrived at the airship the next afternoon, stating that he had news from one of the government spies to the effect that a bold attempt would be made that night.

“They’re going to try and smuggle some diamonds over on this trip,” said the custom agent.

“Well, we’ll try to nab them!” exclaimed Tom.

As soon as it was dark enough to conceal her movements, the Falcon was sent aloft, not a light showing, and, when on high, Tom started the motor at full speed.  The great propellers noiselessly beat the air, and the powerful craft was headed for Lake Ontario.

“They’re pretty good, if they attempted to cross the lake to-night,” observed the young inventor, as he looked at the barometer.

“Why so?” asked Ned.

“Because there’s a bad storm coming up.  I shouldn’t want to risk it.  We’ll keep near shore.  We can nab them there as good as over the lake.”

This plan was adopted, and as soon as they reached the great body of water—­the last in the chain of the Great Lakes—­Tom cruised about, he and Ned watching through powerful night glasses for a glimpse of another airship.

Far into the night they sailed about, covering many miles, for Tom ran at almost top speed.  They sailed over Niagara Falls, and then well along the southern shore of Ontario, working their way north-east and back again.  But not a sign of the smugglers did they see.

Meanwhile the wind had arisen until it was a gale, and it began to rain.  Gently at first the drops came down, until at length there was a torrent of water descending from the overhead clouds.  But those in the Falcon were in no discomfort.

“It’s a bad storm all right!” exclaimed Tom, as he looked at the barometer, and noted that the mercury was still falling.

“Yes, and we have had our trouble for our pains!” declared Mr. Whitford.

“What do you mean?”

“I mean I believe that we have been deceived by a false clew.  The smugglers probably had no intention of getting goods across at this point to-night.  They saw to it that my agent got false information, believing that we would follow it, and leave the vicinity of Logansville.”

“So they could operate there?” asked Tom.

“That’s it,” replied the agent.  “They drew us off the scent.  There’s no help for it.  We must get back as soon as we can.  My!  This is a bad storm!” he added, as a blast careened the airship.