electric
rifles.

The aeroplane, divided into many small packages, the goods for
barter, their supplies, stores, ammunition, and the box of which Tom
took such care--all these were on the backs of the beasts of burden.
Some food was taken along, but for a time, at least, they could
depend on scattered towns or villages, or the forest game, for their
eating.

"Are we all ready?" called Tom, looking at the rather imposing
cavalcade of which he was the head.

"I guess so," replied Ned. "Let her go!"

"Bless my liver pad!" gasped Mr. Damon. "If we've got to start do
it, and let's get it over with Tom."

"All ready, Rad?" asked the colored man's young master.

"All ready, Massa Tom. But I mus' say dat I'd radder hab Boomerang
dan dish yeah animal what I'm ridin'."

"Oh, you'll do all right, Rad. Then, if we're all ready, forward
march!" cried Tom, and with calls to their animals, the drivers
started them off.

Hardly had they begun the advance than Ned, who had been narrowly
watching one of the natives, hurried up to Tom, and rapidly
whispered something to his chum.

"What?" cried Tom. "Armed with a six-shooter, is he? Well, we'll see
about that! Halt!" he cried in Spanish, and then he called San Pedro
the head mule driver, to him.

CHAPTER X

A WILD HORSE STAMPEDE

"Who is that man?" demanded Tom pointing to the one Ned had
indicated. Tom's chum had had a glimpse of a shining revolver in the
hip pocket of one of the mule drivers, and knowing that the simple
natives were not in the habit of carrying such weapons, the lad had
communicated his suspicions to Tom.

"What man, senor?" asked the head mule driver.

"That one!" and the young inventor again pointed toward him. And,
now that Tom looked a second time he saw that the man was not as
black as the other drivers--not an honest, dark-skinned black but
more of a sickly yellow, like a treacherous half-breed. "Who is he?"
asked Tom, for the man in question was just then tightening a girth
and could not hear him.

"I know not, senor. He come to me when I am hiring the others, and
he say he is a good driver. And so he is, I test him before I engage
him," went in San Pedro in Spanish. "He is one good driver."

"Why does he carry a revolver?"

"A revolver, senor? Santa Maria, I know not! I--"

"I'll find out," declared Tom determinedly. "Here," he called to the
offending one, who straightened up quickly. "Come here!"

The man came, with all the