lies were put aboard, spare
garments, all their weapons and ammunition, and then Tom paid
Delazes and his men, giving them a month's wages in advance, for he
told them to wait in camp that long.

"But they won't," the young inventor predicted to Ned.

There was nothing more to be done. All that they could do, to insure
success had been completed. From now on they were in the hands of
fate.

"All aboard!" cried Tom, as he motioned for Eradicate to take his
place in the car. Mr. Damon and Ned followed, and then the young
inventor himself. He shook hands with Delazes, though he did not
like the man.

"Good bye," said Tom. "We may be back before the month is up. If we
are not, go back to Tampico."

"Si, senor," answered the contractor, bowing mockingly.

Tom turned the lever that sent more gas into the bag. The balloon
shot up. The young gold-seeker was about to throw on the motor, when
Delazes waved his hand to the little party.

"Bon voyage!" he called. "I hope you will find the city of gold!"

"Bless my soul!" cried Mr. Damon. "He knows our secret!"

"He's only guessing at it," replied Tom calmly. "He's welcome to
follow us--if he can."

Up shot the aircraft, the propellers whirling around like blades of
light. Up and up, higher and higher, and then forward, while down
below the Mexicans yelled and swung their hats.

Straight for the north Tom headed his craft, so as to throw the
eagerly watching ones off the track. He intended to circle around
and go west when out of sight.

And then the very thing Tom had predicted came to pass. The balloon
was scarcely half a mile high when, as the young inventor looked
down, he uttered a cry.

"See!" he said. "They're breaking camp to follow us."

And it was so. Riding along in one of the lightest ox carts was
Delazes, his eyes fixed on the balloon overhead, while behind him
came his followers.

"They're following us," said Tom, "but they're going to get sadly
left."

In an hour Tom knew his balloon would not be visible to the
Mexicans, and at the end of that time he pointed for the west. And
then, flying low so as to use the trees as a screen, but going at
good speed. Tom and his friends were well on their way to the city
of gold.

"We must keep a good lookout down below," said Tom, when everything
was in working order. "We don't want to fly over the plain of the
ruined temple."

"We may in the night," suggested Ned.

"No night flying this time," said his