last fell down beside the trunk of a tree.

For a moment they lay still, the breath fairly knocked out of them by
the shock. Then they slowly scrambled to their feet, a little shakily,
and looked at each other in disgust.

"Did you ever see such luck as that?" asked Teddy. "Now our goose is
cooked. We'll lose sight of them and that will be the end of it."

"Not by a jugful, it won't," declared Fred, stoutly. "Jump up, and we'll
catch up to them in a jiffy."

He righted the machine, and after leading it through the streak of sandy
road, they mounted and started off. But they had not gone twenty rods
before they began to slow up, and Fred discovered to his dismay that
they were riding on a flat tire.

"We must have had a puncture when the machine fell down," he said as
they jumped off. "It bumped up against the tree, and some projection
jammed into the tire. Here it is now," as he disclosed a tiny opening.

They opened Lester's tool box and set themselves vigorously to work to
repair the puncture. They worked feverishly, and in a minute or two got
out the inner tube and prepared to patch the damaged spot.

"I can do this just as well alone," said Fred. "You take a squint at the
tank and see if we have enough gas to take us on. Lester may have been
nearly out when we grabbed the machine from him."

A groan from Teddy, a moment later, told him that he had hit on an
unpleasant truth.

"Almost empty!" exclaimed Teddy. "There isn't enough to take us another
mile. There's a hoodoo in it. We no sooner see those fellows than we
lose them again."

There was consternation in the boys' eyes as they gazed blankly at each
other.

Fred rose to his feet and looked about him. Half a mile ahead, he saw a
church spire rising above the trees.

"There must be a town over there," he said. "I'll tell you what we'll
do. You skip ahead and find some place where they sell gasoline. Get a
couple of quarts and hustle back. This job will take me ten or fifteen
minutes more, and as soon as I get it done, I'll come on to meet you. If
the gas gives out before I get there, I'll trundle the machine along
until we meet. Get a move on now, for every minute counts."

Teddy started off on a dog trot, and Fred once more bent over his work.
Despite his air of confidence, he had very little hope of picking up the
trail, once the vagrants had gotten out of sight. Still, they could make
inquiries and might have luck. At the very worst they could d