“Start the motor, Ned!” called his chum.  “We’ll see what luck we have!”

Up into the air went the Flyer, her great propellers revolving rapidly.  Over the jungle she shot, and then, when he found that everything was working well, and that the cleaned gas generator was operating as good as when it was new, the young inventor slowed up, and brought the craft down to a lower level.

“For we don’t want to run past these fellows, or shoot over their heads in our hurry,” Tom explained.  “Ned, get out the binoculars.  They’re easier to handle than the telescope.  Then go up forward, and keep a sharp lookout.  There is something like a jungle trail below us, and it looks to be the only one around here.  They probably took that.”  Soon after leaving the place where they had camped after the battle, Tom had seen a rude path through the forest, and had followed that lead.

On sped the Flyer, after the two Englishmen, while Tom thought regretfully of his stolen camera.

CHAPTER XXI — THE JUNGLE FIRE

“Well, Tom, I don’t seem to see anything of them,” remarked Ned that afternoon, as he sat in the bow of the air craft, gazing from time to time through the powerful glasses.

“No, and I can’t understand it, either,” responded the young inventor, who had come for-ward to relieve his chum.  “They didn’t have much the start of us, and they’ll have to travel very slowly.  It isn’t as if they could hop on a train; and, even if they did, I could overtake them in a short time.  But they have to travel on foot through the jungle, and can’t have gone far.”

“’Maybe they have bullock carts,” suggested Mr. Damon.

’The trail isn’t wide enough for that,” declared Tom.  “We’ve come quite a distance now, even if we have been running at low speed, and we haven’t seen even a black man on the trail,” and he motioned to the rude path below them.

“They may have taken a boat and slipped down that river we crossed a little while ago,” suggested Ned.

“That’s so!” cried Tom.  “Why didn’t I think of it?  Say!  I’m going to turn back.”

“Turn back?”

“Yes, and go up and down the stream a way.  We have time, for we can easily run at top speed on the return trip.  Then, if we don’t see anything of them on the water, we’ll pick up the trail again.  Put her around, Ned, and I’ll take the glasses for a while.”

The Flyer was soon shooting back over the same trail our friends had covered, and, as Ned set the propellers going at top speed, they were quickly hovering over a broad but shallow river, which cut through the jungle.

“Try it down stream first,” suggested Tom, who was peering through the binoculars.  “They’d be most likely to go down, as it would be easier.”

Along over the stream swept the airship, covering several miles.

“There’s a boat!” suddenly exclaimed Mr. Nestor, pointing to a native canoe below them.