ness, approaching close to the earth in his noiseless ship several times, and endeavoring to see something through the powerful night glasses. Suddenly, from below them, came a subdued throb and hum of a motor.
"There they are!" exclaimed Mr. Damon.
"I think so," agreed Tom. He looked below. He saw two flickering lights, rather far apart. Mr. Whitford observed them at the same moment.
"There are two of them!" exclaimed the agent, "Two airships, Tom!"
"So I see. Koku get out my electric rifle. We can't chase two, if they separate, so I may have to stop one. It's best to be prepared. I'm going to follow them in the dark, until they get over the border, and then I'll turn on the light and the camera. Then it will be a race to the finish."
The twin lights came nearer. Tom stood with his mouth to the signal tube that communicated with Mr. Damon in the pilot house. From a side window he watched the smugglers' airships. They shot upward and then came on straight ahead, to pass to one side of him. Now they were past. Tom started the wizard camera.
"Half speed ahead!" the young inventor signalled, and the Falcon shot forward. The night race was on.
